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Tesi sul tema "Vegetable oils"
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1
Ramos, Boris. "Production of biodiesel from vegetable oils". Thesis, KTH, Skolan för kemivetenskap (CHE), 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-145863.
Testo completoAbstract (sommario):
The production of biodiesel using vegetables oils is studied. Palm oil and its use for production of biodiesel have been focused. Palm tree is very productive and one of the most profitable for biodiesel production. Among the oilseed crops palm tree produce more oil per hectare. Palm oil has a good availability and a competitive price. The production of palm oil at the industrial plantation level has caused environmental damage. The Roundtable on Sustainable Palm Oil has established principles and criteria in order to certify a sustainable cultivation of the palm oil. The experimental work involves the production of biodiesel using corn oil. Ethanol and methanol are used as alcohols. Sodium and potassium hydroxides are selected as catalyst. The ratio alcohol to oil is the most important parameter in the production of biodiesel. An excess of alcohol is required to drive the reaction to the right. In the experiments with ethanol the yield of biodiesel increased with the ratio ethanol/oil achieving the highest yield at a molar ratio ethanol/oil: 7.78. In the experiments with methanol, using 0.9 g NaOH and 1 hour reaction time the highest yield was obtained with a molar ratio methanol:oil = 9. Using KOH as catalyst and 2 hour reaction time a very good yield is already obtained with a molar ratio methanol:oil = 4.5 The amount of catalyst is another studied parameter. In the experiments with ethanol, the amount of 0.8 mg NaOH and 1.2 mg KOH for 200 ml corn oil (0.22 mol) is enough in order to obtain a good yield. An increase of the amount of catalyst does not produce an increase of the yield of biodiesel. In experiments with methanol, using the lowest tested amount catalyst (0.85 g KOH and 0.23 g NaOH) a good yield of biodiesel is obtained. The effects of the reaction time, rate of mixing and the reaction temperature were studied in the experiments with methanol. The yield of biodiesel increased when the reaction time is increased from 1 to 2 hours. The yield of produced biodiesel increased from 90% to 94% when the rate of mixing was increased from 500 to 1500 rpm. Often the transesterification is carried out at a temperature near the boiling point of alcohol. The highest yield was obtained at 60 oC with KOH and at 55 oC using NaOH but already at 40 oC a good yield was obtained (89%).
2
Sacchetti, Annalisa <1994>. "Catalytic hydrogenation of vegetable oils derivatives". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2022. http://amsdottorato.unibo.it/10070/1/Sacchetti%20Annalisa_final%20upload%20.pdf.
Testo completoAbstract (sommario):
During this project the catalytic hydrogenation of a mixture of fatty acids derivatives was performed in two different reactors (discontinuous batch and continuous flow); the attention was pointed out on the type of the catalyst employed, involving a screening among different noble metals and support with optimization of the reaction parameters.
Interesting results were obtained in batch reactions with 0.3% wt Pd/C at 4 bar of H2 and 90°C, ensuring full conversion of the starting material and complete selectivity towards the saturated compounds. An insight of the kinetics of the reaction was performed, conducting the reaction for different time (0-6 hours). Also, fundamental parameters such as H2 pressure, stirring rate, temperature, metal type and support were evaluated for determining the most advantageous conditions to guarantee complete starting material conversion and high yields of desired products. The same tests were then performed employing a continuous flow reactor, confirming the high activity of 0.3% wt Pd/C at low contact time of 0.2 min.
Despite stunning results were achieved with a single batch (discontinuous) or for low reaction time (1h in continuous), the catalyst performance started to worsen for multiple batch or longer time respectively. Investigations on the cause were executed, excluding immediately metal leaching thanks to ICP-AES analysis. Deactivation was attributable to absorption of reactants on the catalyst surface, which could lead to formation of oligomers. It was found that the deactivation rate, in the continuous reactor, was directly dependent on the hydrogen pressure, the contact time but even more importantly to the composition of the starting material: an increase of poly-unsaturated fatty acids derivatives affected negatively the catalyst stability, causing a faster decline of conversion and higher decrease in selectively. This was associated to a strong adsorption with consequent formation of oligomers, which occupied the active site, worsening the catalyst’s performance.
3
Roy, Dibakar. "Modification of vegetable oils as a potential base oil and a multifunctional lube oil additive". Thesis, University of North Bengal, 2021. http://ir.nbu.ac.in/handle/123456789/4365.
Testo completo
4
Good, Joanne Elizabeth. "Replacement of dietary fish oil with vegetable oils : effects on fish health". Thesis, University of Stirling, 2004. http://hdl.handle.net/1893/2005.
Testo completoAbstract (sommario):
The work presented in this thesis examined the effects of dietary fish oil replacement on fish innate and adaptive immune function, disease resistance tissue histopathology and fatty acid composition of lipids in peripheral blood leukocytes. Dietary trials with Atlantic salmon (Salmo salar), Sea bass (Dicentrarchus labrax), Atlantic cod (Gadus morhua) and Arctic char (Salvelinus alpinus) were conducted in which fish oil was replaced by rapeseed oil, linseed oil, olive oil, palm oil, echium oil or a mixture of these oils. A significant reduction in respiratory burst activity was most pronounced in salmon and sea bass fed high levels of rapeseed oil-containing diets. In addition, rapeseed and olive oil inclusion in the diets of salmon and sea bass significantly reduced the head kidney macrophage phagocytic capacity to engulf yeast particles. A reduction in prostaglandin E2 levels was found to be related to a reduction in macrophage respiratory burst activity in salmon fed linseed oil diets and sea bass fed a dietary blend of linseed, palm and rapeseed oils. Changes in macrophage function may be a contributing factor causing a reduction in serum lysozyme activity observed in some trials. No significant differences were detected in cumulative mortality of Atlantic salmon fed an equal blend of linseed and rapeseed oils challenged with Aeromonas salmonicida. However, resistance to Vibrio anguillarium was significantly impaired in Atlantic salmon fed a blended oil diet containing linseed, rapeseed and palm oil. The major histological difference of fish fed vegetable oil diets was the accumulation of lipid droplets in their livers. Dietary fatty acid composition significantly affected the fatty acid composition of peripheral blood leukocytes. Generally, fish fed vegetable oil diets had increased levels of oleic acid, linoleic acid and a-linolenic acid and decreased levels of eicosapentaenoic acid, docosahexaenoic acid and a lower n-3/n-6 ratio than fish fed a FO diet. In conclusion, the results from these studies suggest that farmed fish species can be cultured on diets containing vegetable oils as the added oil source. However, feeding high levels of some vegetable oils may significantly alter some immune responses in the fish, especially head kidney macrophage function, disease resistance and, in addition, may cause an increase in tissue histopathology.
5
Lligadas, Puig Gerard. "Biobased thermosets from vegetable oils. Synthesis, characterization and properties". Doctoral thesis, Universitat Rovira i Virgili, 2006. http://hdl.handle.net/10803/9007.
Testo completoAbstract (sommario):
Biobased Thermosets from Vegetable Oils. Synthesis, Characterization, and PropertiesGerard Lligadas Puig
El desenvolupament sostenible va esdevenir com una de les idees claus del segle 20. S'entén per desenvolupament sostenible aquell tipus de desenvolupament que és capaç de satisfer les necessitats actuals sense comprometre els recursos i possibilitats de les futures generacions. Per assolir un desenvolupament sostenible és necessari promoure un desenvolupament social i econòmic pendent en tot moment del medi ambient.
La conservació i la gestió dels residus és especialment important en aquest procés. La creixent demanda de productes derivats del petroli, juntament amb la disminució progressiva de les reserves de petroli són algunes de les moltes raons que han encoratjat la industria química a començar a utilitzar les fonts renovables com a matèria prima.
En aquest context, en els darrers anys l'atenció s'ha centrat en la utilització de recursos anualment renovables, com són els recursos agrícoles, en la producció d'una gran varietat de productes industrials. Un dels recursos renovables més interessants per a la indústria química són els olis vegetals degut a la seva elevada disponibilitat i el seu ampli ventall d'aplicacions. Els olis vegetals formen part de la família de compostos químics coneguts com lípids, i estan constituïts majoritàriament per molècules de triglicèrids. Els triglicèrids estan formats per tres molècules d'àcid gras unides a una molècula de glicerol mitjançant enllaços ester. Els àcids grassos que es troben en la majoria d'olis vegetals estan constituïts per cadenes alifàtiques insaturades de entre 14 i 22 àtoms de carboni.
La explotació industrial dels recursos naturals està actualment en el punt de mira de la comunitat científica. Concretament, el desenvolupament de materials polimèrics derivats de fonts renovables està rebent un interès creixent degut a la incertesa en el preu i les reserves de petroli. La substitució del petroli per productes derivats de fonts renovables és consistent amb el concepte de desenvolupament sostenible.
El propòsit del treball portat a terme en aquesta tesi doctoral va ser desenvolupar nous materials termoestables utilitzant olis vegetals com a productes de partida. En el capítol 1 es discuteix la contribució de la química en el desenvolupament sostenible i es descriuen les possibilitats dels olis vegetals com a productes de partida en la síntesi de materials polimèrics. El capítol 2 descriu la preparació de dos noves famílies de materials híbrids orgànics-inorgànics derivats d'olis vegetals. Es descriu síntesi i caracterització de polímers híbrids derivats d'àcids grassos que contenen dobles enllaços carboni-carboni terminals utilitzant la reacció d'hidrosililació com a reacció d'entrecreuament, i la preparació de polímers derivats d'oli de llinosa epoxidat nanoreforçats amb silsesquioxans polièdrics. En el capítol 3 es descriu la síntesi d'un nou compost fosforat derivat de fonts renovables. Aquest compost s'ha utilitzat com a compost retardant a la flama reactiu en la preparació de resines epoxi derivades de fonts renovables amb propietats de resistència a la flama. La incorporació de fòsfor en resines epoxi d'aquest tipus ha donat lloc a polímers amb bones propietats de resistència a la flama. Finalment, en el capítol 4 es descriu la preparació d'una nova família de polièter poliols derivats d'oleat de metil epoxidat com a font renovable. Aquests poliols s'han utilitzat en la síntesi de poliuretans amb aplicacions específiques: poliuretans que incorporen silici amb propietats de resistència a la flama, i poliuretans segmentats amb aplicacions en biomedicina.
Biobased Thermosets from Vegetable Oils. Synthesis, Characterization, and Properties
Gerard Lligadas Puig
Sustainable development, which became a key idea during the 20th century, may be regarded as the progressive and balanced achievement of sustained economic development, and improved social equity and environmental quality. Sustainable development comprises the three components of society, environment, and economy, and its goals can only be achieved if all three components can be satisfied simultaneously.
The conservation and management of resources is especially important to this process. The growing demand for petroleum-based products and the resulting negative impact on the environment, plus the scarcity of non-renewable resources, are some of the many factors that have encouraged the chemical industry to begin using renewable resources as raw materials.
This situation has led to considerable attention being focused recently on the use of annually renewable agricultural feedstock to produce a wide range of base chemicals and other industrial products. The renewable raw materials that are most important to the chemical industry are natural oils and fats because of their high availability and versatile applications. Vegetable oils constitute about 80% of the global oil and fat production, with 20% (and declining) being of animal origin. The use of these materials offers an alternative approach that is both sustainable and, with the right application, far more environmentally benign than fossil sources.
Vegetable oils and fats form part of a large family of chemical compounds known as lipids. Vegetable oils are predominantly made up of triglyceride molecules, which have the three-armed star structure. Triglycerides comprise of three fatty acids joined at a glycerol junction. Most of the common oils contain fatty acids that vary from 14 to 22 carbons in length, with 0 to 3 double bonds per fatty acid.
Research into the industrial exploitation of products derived from renewable resources is currently of immense international importance. In particular, the development of polymer materials from renewable resources is receiving considerable attention since the availability of crude oil will become severely restricted within the foreseeable future. The replacement of crude oil by renewable raw materials is also consistent with the aim of global sustainability.
The purpose of the study reported in this thesis was to develop new biobased thermosetting polymers from vegetable oils as renewable resources. To achieve this goal, the experimental work focused on exploiting the reactivity of unsaturated fatty compounds. Chapter 1 discusses the contribution of chemistry to sustainable development, and also presents an overview of recent developments in the chemistry of vegetable oil-based polymers. Chapter 2 describes the preparation of two new types of organic-inorganic hybrid materials from vegetable oils. Hybrids with promising properties for optical applications were prepared by the hydrosilylation of alkenyl-terminated fatty acid derivatives with several hydrosilylating agents, and the first example of the preparation of biobased polyhedral oligomeric silsesquioxanes-nanocomposites from vegetable oil derivatives is reported. Chapter 3 describes the synthesis of a new phosphorus-containing fatty acid derivative. This compound is used as a reactive flame-retardant in the preparation of flame-retardant epoxy resins from terminal epoxy fatty acid derivatives. The incorporation of phosphorous into biobased epoxy resins yields polymers with good flame-retardant properties. Finally, chapter 4 describes the preparation of a new family of epoxidized methyl oleate based polyether polyols. These polyols are used in the synthesis of polyurethanes, some with specific applications: silicon-containing polyurethanes with enhanced flame-retardant properties, and polyurethane networks with potential applications in biomedicine.
6
Fernandes, Vanda Filipa Silva. "Characterization of biodiesels produced from mixtures of vegetable oils". Master's thesis, Universidade de Aveiro, 2010. http://hdl.handle.net/10773/3141.
Testo completoAbstract (sommario):
Mestrado em Engenharia QuímicaNos últimos anos o biodiesel tem recebido uma atenção notável devido à sua capacidade de substituir os combustíveis fósseis. É considerado um amigo do ambiente, devido às suas imensas vantagens. Este biocombustível é obtido a partir de recursos renováveis, portanto é considerado biodegradável, CO2-neutro, nãotóxico e reduz significativamente as emissões gasosas com efeito de estufa. É composto por uma mistura de ésteres mono alquílicos obtidos a partir de óleos vegetais, tais como, o óleo de soja, óleo de jatropha, óleo de colza, óleo de palma, óleo de girassol ou a partir de outras fontes como a gordura animal (sebo, banha), restos de óleo e gorduras de cozinha. O processo mais comum para a sua produção é através de uma reacção de transesterificação, onde o óleo vegetal reage com um álcool de cadeia curta na presença de um catalisador. Devido às suas propriedades muito semelhantes ao diesel, são mutuamente miscíveis e assim podem ser misturados em qualquer proporção em ordem a melhorar as suas qualidades. O conhecimento das suas propriedades termofísicas como a densidade e viscosidade, que são afectadas pela temperatura, são muito importantes para a indústria automóvel. Contudo, o biodiesel apresenta algumas desvantagens como elevada densidade, viscosidade, ponto de turvação e escoamento/fluxação em comparação com diesel fuel. O seu comportamento a baixas temperaturas limita a sua aplicação em climas frios, sendo que este comportamento é influenciado pelas matérias-primas e álcool utilizado no processo de produção. Os biodieseis obtidos a partir de óleos com grande teor de ácidos gordos saturados induzem a um pior desempenho a baixas temperaturas, visto que são compostos sólidos a temperaturas mais baixas. Neste trabalho, misturas binárias e ternárias de biodiesel de soja, colza e palma, e diesel fuel foram preparadas e medidas as suas viscosidades dinâmicas e densidade em função da temperatura. Para prever as densidades e viscosidades a partir dos compostos puros são utilizadas regras de mistura. O comportamento a baixas temperaturas dos três biodieseis foi estudado. Onde a composição da fase líquida e sólida e a fracção de sólidos a temperaturas abaixo do ponto de turvação foram analisadas. Aplicou-se um modelo termodinâmico para descrever estes sistemas multifásicos e outros sistemas idênticos. Duas versões do modelo preditivo UNIQUAC, juntamente com uma abordagem que assume uma completa miscibilidade dos componentes na fase sólida, são avaliados em relação aos dados de equilíbrio de fases experimentais medidos. ABSTRACT: In recent years, biodiesel has received a notable attention due its ability to replace fossil fuels. It is considered an environmental friendly due their vast advantages. This biofuel is obtained from renewable resources, so it is considered biodegradable, CO2- neutral, non-toxic and significantly reduces the greenhouse gas emissions. It is composed by a mixture of mono alkyl esters obtained from vegetable oil, such as, soybean oil, jatropha oil, rapeseed oil, palm oil, sunflower oil or from other sources like animal fat (beef tallow, lard), waste cooking oil and grasses. The most common process for its production is by a transesterification reaction, where the vegetable oil reacts with a short chain alcohol in presence of a catalyst. Due to its properties very similar to diesel fuel, they are mutually miscible and so can be mixed in any proportion in order to improve its qualities. The knowledge of its thermophysical properties like density and viscosity, which are affected by temperature, is very import for automotive industries. However, biodiesel present some disadvantages like higher viscosity, density, cloud and pour point compared with diesel fuel. Its behaviour at low-temperature limiting its application in cold climate and these behaviour is influenced by raw materials and the alcohol used in production process. The biodiesel obtained from oils with a major level in saturated fatty acids esters induce a worse behaviour at low temperatures, since they are solid compounds at lower temperatures. In this work, binary and ternary blends of biodiesel of soybean, rapeseed and palm, and diesel fuel were prepared and its dynamic viscosities and densities were measured in function of temperature. Mixing rules are used for predicting the densities and viscosities from pure compounds. The low temperature behaviour of three biodiesel was studied. The liquid and solid phase compositions and solid fraction at temperatures below the cloud point were analyzed. A thermodynamic model was applied to describe these multiphase systems and other similar systems. Two versions of the predictive UNIQUAC model along with an approach that assuming complete immiscibility of the compounds in the solid phase are evaluated against the experimental phase equilibrium data measured.
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Valverde, Marlen A. "Green plastics, rubbers, coatings, and biocomposites from vegetable oils". [Ames, Iowa : Iowa State University], 2009. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3389154.
Testo completo
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Myint, Lay L. "Process analysis and optimization of biodiesel production from vegetable oils". [College Station, Tex. : Texas A&M University, 2007. http://hdl.handle.net/1969.1/ETD-TAMU-1267.
Testo completo
9
Gamage, Padmasiri Kankanam. "Use of selected vegetable oils as plasticiser/stabiliser for PVC". Thesis, London Metropolitan University, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.507082.
Testo completo
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Hu, Chaohe. "Versatile biobased particles of acrylate vegetable oils : Synthesis and applications". Thesis, université Paris-Saclay, 2022. http://www.theses.fr/2022UPAST081.
Testo completoAbstract (sommario):
Depuis ses débuts, au début des années 1920, l'industrie des polymères dépend fortement des ressources en combustibles fossiles. Environ 4 à 8 % du pétrole, du gaz et de leurs dérivés sont aujourd'hui transformés en matériaux polymères. La plupart d'entre eux sont non recyclables et non dégradables, ce qui entraîne de graves problèmes environnementaux, préjudiciables à la faune et à l'homme. Dans ce contexte, il est nécessaire de développer des produits polymères alternatifs qui, à partir de matières premières renouvelables, présenteront le même niveau de complexité que les produits actuels issus de l'industrie pétrolière.Parmi les différentes matières premières biosourcées utilisées pour fabriquer des matériaux polymères, les huiles végétales sont prometteuses pour leur faible coût et leur dégradabilité intrinsèque, mais aussi parce que leur production est déjà optimisée pour l'industrie alimentaire. L'huile de soja époxydée acrylée (AESO) est un exemple des dérivés d'huiles végétales qui sont utilisés comme additifs plastifiants pour la formulation du PVC. Seule, l'AESO peut être facilement et rapidement polymérisée pour donner un polymère thermodurci. Cependant, en raison de sa viscosité intrinsèque élevée, la plupart des recherches sur les polymères à base d'AESO se sont concentrées jusqu'à présent sur les propriétés de masse, de revêtement ou de film de ce matériau, laissant dans l'ombre la possibilité de fabriquer des matériaux à haute valeur ajoutée.Ce travail se concentre sur la fabrication et l'application des microparticules d'AESO. Nous présentons d'abord une approche simple à travers un mélangeur vortex pour préparer les particules AESO polydispersées basées sur la photopolymérisation en émulsion. Les microparticules AESO synthétisées présentent une bonne dégradabilité dans des conditions chimiques et enzymatiques. Ensuite, nous développons un dispositif microfluidique " one pot " avec une structure de focalisation du flux pour l'émulsification et une zone serpentine pour la réticulation induite par les UV, qui peut être utilisé pour produire en continu des particules AESO monodispersées avec une taille réglable. Nous démontrons également la méthode basée sur les puces microfluidiques modifiées pour préparer les particules non sphériques, où une puce avec une jonction de focalisation d'écoulement en forme de Y est utilisée pour préparer les particules AESO en forme de croissant et une autre puce avec une double jonction de focalisation d'écoulement est utilisée pour synthétiser les particules AESO structurées en coquille de trou. De plus, des microcapsules d'AESO sont fabriquées par la puce personnalisée et elles sont disponibles pour encapsuler des solutions ou des substances aqueuses. Enfin, nous montrons la capacité des microparticules AESO à transporter les molécules organiques dans leurs réseaux réticulés et utilisons des méthodes similaires pour charger les médicaments (curcumine et ibuprofène). Le comportement de libération des médicaments dans le fluide corporel simulé peut être observé, ce qui peut constituer un support prometteur pour d'autres applications pharmaceutiquesSince its beginning, in the early 1920's, polymeric industry relies heavily on fossil fuel resources. Approximately 4%-8% oil, gas and their derivatives are nowadays transformed into polymeric materials. Most of them are non-recyclable and non-degradable, hence leading to serious environmental issues, detrimental to wildlife and humans. In this context, there is a need for the development of alternative polymeric products, which, starting from renewable commodities, will share the same level of complexity than current ones derived from oil industry.Among the various bio-sourced raw products used to make polymeric materials, vegetable oils are promising for their low cost and intrinsic degradability, but also because their production is already optimized for the food industry. Acrylated epoxidized soybean oil (AESO) is one example of the vegetable oil derivatives that are used as e.g. plastifying additives for the formulation of PVC. Alone, AESO can be readily and rapidly polymerized to give a thermoset polymer. However, as a consequence of its high intrinsic viscosity, most of the research on AESO-based polymer so far is only focused on the bulk, coating or film properties of this material, leaving the possibility to fabricate high added value materials a blind spot.Herein, this work focuses on the fabrication and application of the AESO microparticles. We first present a simple approach through a vortex mixer to prepare the polydispersed AESO particles based on the emulsion photopolymerization. The synthesized AESO microparticles present a good degradability in the chemical and enzymatic conditions. Then, we develop a “one pot” microfluidic device with a flow-focusing structure for emulsification and the serpentine zone for UV-induced reticulation, which can be used to continuously product the monodispersed AESO particles with a tunable size. We also demonstrate the method base on the modified microfluidic chips to prepare the non-spherical particles, where a chip with Y-shape flow-focusing junction is used to prepare the crescent-shaped AESO particles and another chip with a double flow-focusing junction is utilized to synthesize the hole-shell structured AESO particles. In addition, AESO microcapsules are fabricated by the customized chip, and they are available to encapsulate the aqueous solutions or substances. Finally, we show the ability of AESO microparticles to carry the organic molecules into their crosslinked networks and use the similar methods to load the drugs (curcumin and ibuprofen). The release behavior of drugs in simulated body fluid can be observed, which may be act as a promising drug carrier for further pharmacy applications
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Piccolo, Damiano. "Epoxidation of vegetable oils by conventional and non-conventional methods". Doctoral thesis, Università degli studi di Padova, 2020. http://hdl.handle.net/11577/3425915.
Testo completoAbstract (sommario):
The interest on epoxidised vegetable oils has been increasing in the last years thanks to their use as renewable and sustainable resource for a wide range of environmental-friendly and sustainable chemicals. The aim of this work is producing epoxidised soybean oil in newer, safer and more efficient ways. This PhD thesis is structured according to different experimental approaches, supported by a kinetic and mass transfer modelling to enable a complete understanding of the phenomena. The epoxidation process was carried out in two phases via peroxyacetic acid, produced by the reaction between acetic acid and hydrogen peroxide. Epoxidation of soybean oil was carried out in a batch calorimetric reactor, for an accurate study on kinetics, mass transfer and calorimetry. Furthermore, the microwave (MW) heating effect on the process was studied, by means of a comparative study using two geometrically similar reactors with different heating sources, conventional and MW heating. MW heating process is able to produce a uniform stable suspension halving the time to reach maximum yield. Epoxidation was tested also in a continuous system, for its potential industrial interest. The process was also effective in a continuous reactor, even though the mixture must be stabilised by means of a surfactant. The feasibility of using radiofrequency heating in the continuous reactor was tested for more controlled operation than MW heating.
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McLellan, Jill Fraser. "Ene addition reactions involving jojoba bean oil, triglyceride vegetable oils and synthetic lubricant fluids". Thesis, University of Edinburgh, 1995. http://hdl.handle.net/1842/11137.
Testo completoAbstract (sommario):
Ene addition reactions involving jojoba bean oil (a wax ester), sunflower oil (a triglyceride) and the synthetic fluids polyisobutene and polyalphaolefin have been investigated. Several enophiles have been employed, including azo compounds [diethyl azodicarboxylate (DEAD), 4-phenyl-1-1,2,4-triazoline-3,5-dione (PTAD) and 4-methyl-1,2,4-triazoline-3,5-dione (MTAD)], a sulfinyl compound [N-sulfinyl-p-toluenesulfonamide (TosNSO)] and formaldehyde. In order to investigate the scope of these reactions, and to gain spectral information for use in the analysis of more complex product mixtures, model alkenes were studied. For this purpose, methyl oleate, methyl elaidate and oleyl acetate were chosen, as were the symmetrical simple alkenes 3-hexene and 5-decene, and a series of terminal alkenes. In each case, identification and characterisation of addition products was achieved principally by NMR (IH and 13C) and FAB mass spectroscopy. Addition of the azo enophiles to jojoba oil and the mono-ene models resulted, in most cases, in the formation of adducts containing an alkene double bond with exclusively trans configuration. The exception to this was the addition of DEAD to 1-alkenes which resulted in adducts with ca. 20% of cis units. Where the lipid ene components were unsymmetrically substituted, the products were formed as 1:1 mixtures of regioisomers, as determined by high field 13C NMR spectroscopy. Kinetic measurements were made on the relative reactivities towards PTAD of methyl oleate, methyl elaidate, jojoba and trans-jojoba by two methods: using UV-visible spectroscopy to follow the consumption of the enophiles and secondly, by monitoring the relative rates of disappearance of lipid components by capillary gas chromatography. These measurements confirmed the visual observation that cis ene components reacted more quickly with PTAD than those with trans geometry. On reaction of the azo compounds with methyl linoleate, three major adduct types were isolated: non-conjugated dienes, conjugated dienes and diadducts resulting from a tandem ene/Diel-Alder cycloaddition. The ratio of these three adduct types was found to vary depending on the enophile. With the triazolines the non-conjugated dienes and tandem diadducts predominated while, conversely, for DEAD the conjugated dienes were the major products.
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Tabee, Elham. "Lipid and phytosterol oxidation in vegetable oils and fried potato products /". Uppsala : Department of Food Science, Swedish University of Agricultural Sciences, 2008. http://epsilon.slu.se/200892.pdf.
Testo completo
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Trullàs, Huguet Clara. "Used of acid and re-esterified vegetable oils in fish diets". Doctoral thesis, Universitat Autònoma de Barcelona, 2016. http://hdl.handle.net/10803/368235.
Testo completoAbstract (sommario):
La utilització d’olis natius d’origen vegetal (VO) en dietes per peixos com a substituts de la font lipídica tradicionalment utilitzada, l’oli de peix (FO), es veu limitada degut a la creixent demanda per part de les indústries de pinsos, aliments i biocombustibles.
Els olis àcids són un subproducte ric en àcids grassos lliures provinent del procés de refinació d’olis vegetals que poden ser fonts alternatives interessants a la utilització d’VO. Malgrat això, la seva utilització com a font lipídica en dietes per animals monogàstrics presenta controvèrsia. Els olis àcids vegetals poden ser re-esterificats químicament amb glicerol per produir olis vegetals re-esterificats, que tenen diferents proporcions de mono- (MAG), di- (DAG) i triglicèrids (TAG). A més, els olis vegetals re-esterificats tenen una estructura molecular diferent de la del seu corresponent VO natiu i per tant adquireixen noves propietats físico-químiques que poden ser interessants des d’un punt de vista nutricional. Per tot això, l’objectiu d’aquesta tesi va ser el d’investigar la utilització d’VO àcids i re-esterificats en dietes per peixos.
La caracterització dels olis experimental (Capítols 1 al 7) va mostrar que els VO re-esterificats tenen una major proporció de MAG i DAG, a més d’una major proporció d’àcids grassos saturats (SFA) en la posició 2 (sn-2) de les seves molècules d’acil glicerols que els seus corresponents olis natius.
Als dos primers experiments (Capítols 3 i 4) es va estudiar la utilització en dietes d’olis àcid i re-esterificat (baix o alt en MAG i DAG). Els seus efectes sobre el coeficient de digestibilitat aparent (ADC) dels àcids grassos totals en truita irisada (Capítol 3) i orada (Capítol 4) va ser avaluada en comparació al corresponent oli natiu. Els peixos alimentats amb la dieta amb oli àcid van tenir un ADC inferior que aquells alimentats amb les dietes amb oli natiu o re-esterificats en ambdues espècies.
En truita irisada, les dietes amb olis re-esterificats de palma no van resultar en un ADC dels àcids grassos totals diferents d’aquelles amb oli natiu. En la colza, els ADC dels àcids grassos totals van ser alts (96.4-98.1%) en tots els casos, tot i que aquells dels peixos alimentats amb la dieta amb oli natiu van resultar superiors als dels peixos alimentats amb la dieta amb oli re-esterificat baix en MAG/DAG. En orada, els animals alimentats amb la dieta amb oli natiu van mostrar un ADC dels àcids grassos totals inferior al de la dieta amb oli re-esterificat baix en MAG/DAG. Pel que fa a la colza, els peixos alimentats amb olis re-esterificats no van presentar diferències en el ADC dels àcids grassos totals respecte a aquells alimentats amb la dieta amb oli natiu.
En general, la digestibilitat dels àcids grassos dels olis experimentals es va veure més afectada pel seu grau d’insaturació que per la seva distribució posicional o la seva composició en fraccions lipídiques.
Al tercer experiment, (Capítols 5, 6 i 7), en base als bons resultats obtinguts amb les dietes amb olis àcid o re-esterificats, es va estudiar la seva utilització en dietes, en combinació amb un 5% de FO. Amb aquesta finalitat, els olis experimentals es van incloure en les dietes com a única fot lipídica o en combinacions de l’oli àcid amb l’oli natiu o amb l’oli re-esterificat (alt en MAG i DAG). Els seus efectes sobre el ADC del greix i dels àcids grassos totals, creixement, paràmetres plasmàtics, morfologia de fetge i intestí (Capítol 5), qualitat del filet (Capítol 6) i composició en àcids grassos totals i en sn-2 del teixits (Capítol 7) van ser avaluats. Els resultats no van mostrar efectes rellevants de les dietes experimentals sobre els paràmetres mencionats en comparació amb la dieta amb oli natiu. Tot i així, malgrat que els pesos finals dels peixos van ser alts en tots els casos, aquells dels animals alimentats amb dietes de colza no van arribar als dels peixos alimentats amb la dieta amb FO. A més d’això, a major presència d’oli àcid en les dietes menor pes final dels animals.
Per tot això, la inclusió d’olis àcid i re-esterificats d’origen vegetal en dietes per peixos és una alternativa interessant a la utilització d’olis natius quan provinguin d’una font insaturada com la colza.SUMMARY The use of native vegetable oils (VO) in fish diets as substitutes of the traditionally used lipid source, fish oil (FO), has limitations due to their growing demand by feed, food and biofuel industries. Acid VO are a rich-in-free fatty acid (FFA) by-product from the refining of crude VO that can be interesting alternatives to native VO. However, its use as lipid sources in monogastric animal diets appears to be controversial. Acid VO can be chemically re-esterified with glycerol in order to obtain re-esterified VO, which have different proportions of mono- (MAG), di- (DAG) and triacylglycerols (TAG). Moreover, re-esterified VO have a different molecular structure than their corresponding native VO and thus acquire new physico-chemical characteristics that can be interesting from a nutritional point of view. Thus, the aim of this dissertation was to investigate the use of acid and re-esterified VO in fish diets. The experimental oils and diets characterization (Chapters 1 to 7), showed that re-esterified VO have a higher proportion of MAG and DAG and a higher proportion of saturated fatty acids in the sn-2 position of acylglycerol molecules than the corresponding native VO. In the first two trials (Chapters 3 and 4) the dietary use of palm or rapeseed acid and re-esterified (low or high in MAG and DAG) oils was assessed. Their effect on total fatty acid apparent digestibility coefficients (ADC) in rainbow trout (Chapter 3) and gilthead sea bream (Chapter 4) was evaluated in comparison with the corresponding native oils. Fish fed acid oil diets had lower ADC than those fed native or re-esterified oils diets in both species. In rainbow trout, diets containing palm re-esterified oils did not result in different total fatty acid ADC than those containing palm native oil. For rapeseed, total fatty acid ADC were high (96.4-98.1%) in all cases, although that of fish fed the native oil diet was higher than that of fish fed the re-esterified oil low in MAG/DAG diet. In gilthead sea bream, fish fed the native palm oil diet had a lower total fatty acid ADC than the re-esterified oil high in MAG/DAG diet. Regarding rapeseed, fish fed re-esterified oils diets did not have different total fatty acid ADC than those fed the native oil diet. Overall, fatty acid digestibility of the experimental oils seemed to be more affected by their degree of unsaturation than by their positional distribution or lipid class composition (TAG, MAG, DAG and FFA). In the third trial (Chapters 5, 6 and 7), on the basis of the good results obtained with the acid or re-esterified oils diets, their dietary use when combined with 5% FO was evaluated. The experimental oils were included in diets as a sole lipid source or in blends of the acid with the native or the re-esterified (high in MAG and DAG) oil. Their effects on fat and total fatty acid ADC, growth performance, plasma parameters, morphology of liver and intestine (Chapters 5), fillet quality (Chapter 6) and total and sn-2 fatty acid composition of tisues (Chapter 7) were assessed. Results showed no relevant effects of the experimental oils diets on the aforementioned parameters compared to the native oil diet. However, although fish final weights were high in all cases, those of fish fed rapeseed diets did not reach values obtained by fish fed the FO diet. Moreover, the higher presence of acid oil in diets, the lower the fish final weight. All things considered, the inclusion of acid and re-esterified VO in fish diets is an interesting alternative to the use of native VO when they are produced from a unsaturated source such as rapeseed.
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Castagnino, Pablo de Souza [UNESP]. "In vitro fermentation parameters and biohydrogenation of vegetable oils without glycerol". Universidade Estadual Paulista (UNESP), 2014. http://hdl.handle.net/11449/113760.
Testo completoAbstract (sommario):
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000803371.pdf: 600837 bytes, checksum: 850c380a2ac98e37fd93bb85fc37039a (MD5)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
O glicerol combinado com óleos vegetais poderia limitar a intensa biohidrogenação dos ácidos graxos de cadeia longa e a produção de metano sem causar efeitos deletérios sobre a população microbiana e digestibilidade. Três incubações in vitro foram conduzidas para avaliar o efeito do glicerol (0 or 150 g/kg MS) combinado com três diferentes dietas: Feno de Tifton 85 sem a inclusão de óleo (FSO), Feno de Tifton 85 + 80g de óleo de soja/kg MS (FOS) e Feno de Tifton 85 + 80 g de óleo de linhaça/kg MS (FOL) incubados por 0, 6, 12 e 24 h sobre a composição de ácidos graxos e os parâmetros de fermentação ruminal. A PCR em tempo-real (qPCR) foi utilizado para quantificação de microorganismos às 24 h. As arquéias metanogênicas ,bactérias celulolíticas e lipolíticas foram expressas em função das bactérias totais. Separadamente, a cinética de produção de gases foi avaliada nos tempos 2, 4, 6, 8, 10, 12, 14, 18, 22, 24, 36, 42 e 48 h. A digestibilidade verdadeira in vitro (DVIV) e a produção CH4 (%/g DMS) foram avaliadas às 48 h. Os valores de pH e as concentrações de amônia (NH3-N) foram menores nas dietas FSO comparado com FOS e FOL, independente da adição de glicerol (P<0,05). A proporção da Anaerovibrio lipolytica aumentou 84, 33 e 13 vezes nas dietas FSO, FOS e FOL com adição de glicerol, respectivamente, comparadas com as dietas sem glicerol (P<0,05). Ruminococcus albus, Ruminococcus flavefaciens e os subgrupos Butyrivrio VA e SA subgroup não foram alteradas com a inclusão dos óleos vegetais e de glicerol (P>0,05). As bactérias Fibrobacter succinogenes foram mais sensíveis a adição de óleos vegetais entre todas as bactérias celulolíticas (P<0,05). A DVIV e a produção de CH4 foram inferiores nas dietas FOS com adição de glicerol e na dieta FOL independente da adição de glicerol (P<0,05). A redução na produção de gases ocorreu nas dietas FOS e FOL associadas com glicerol ...
Glycerol combined with vegetable oils could limit biohydrogenation and enhance the reduction in methane production without depressing digestibility and microbial population. Three in vitro incubations were conducted to evaluate the effect of glycerol (0 or 150 g/kg DM) combined with three different diets: Tifton 85 hay without oil seeds (HWO), Tifton 85 hay + 80g of soybean oil/kg DM (HSO) and Tifton 85 hay + 80 g of linseed oil/kg DM (HLO) incubated for 0, 6, 12 and 24 h on fatty acid composition and ruminal fermentation parameters. Real-time PCR was used to quantify microbial population at 24 h. Methanogens, fibrolitic and lipolityc bacteria were expressed as a proportion of total rumen bacterial 16 S rDNA. Separately, kinetic of gas production was assessed at 2, 4, 6, 8, 10, 12, 14, 18, 22, 24, 36, 42 and 48 h. In vitro true digestibility (IVTD) and CH4 (%/g DMD) production were evaluated at 48 h. The experimental design for fatty acid composition and ruminal parameters was a randomized block in a factorial arrangement 2 x 3 x 4, involving the following factors: glycerol (2), diets (3) and time (4). Microbial quantification, IVTD and CH4 were evaluated with the same design but without time as a factor. The pH value and ammonia (NH3-N) concentration were lower in HWO compared with HSO and HLO diets, regardless of glycerol addition (P<0.05). Anaerovibrio lipolytica proportion increased 84, 33 and 13 times in HWO, HSO and HLO diets with glycerol, respectively, compared with diets without glycerol (P<0.05). Ruminococcus albus, Ruminococcus flavefaciens and Butyrivrio VA and SA subgroup did not change with glycerol and oil addition (P>0.05). Among all cellulolytic bacteria, Fibrobacter succinogenes was the most sensitive to the addition of vegetable oil in the diet (P<0.05). CH4 production decreased in HSO diet associated with glycerol and HLO diets with or without glycerol addition (P<0.05). Lag time decreased in HWO and HSO diets ...
FAPESP: 12/13122-4
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Zuta, Charles Prince. "Synthesis of novel triglycerides from mackerel by-products and vegetable oils". Thesis, McGill University, 2003. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=84863.
Testo completoAbstract (sommario):
The study was designed to develop a nutraceutical product from by-products of fish processing. Fish oil was extracted from mackerel tissues (skin, viscera and muscle) using hexane-isopropanol (3:2 v/v) and chloroform-methanol (2:1 v/v) solvent systems. An oxidative study was carried out to determine the best processing and storage conditions to minimize autooxidation of mackerel oil. Urea complexation was used to concentrate polyunsaturated fatty acids (PUFA) from the extracted fish oil. The urea complexation process was optimized to determine the best reaction conditions for high yield of the omega-3 fatty acids in particular, and total PUFA.Conjugated linoleic acid (CLA) was synthesized from four vegetable oils (sunflower, canola, soybean and corn) by alkaline isomerization. The CLA isomers and PUFA concentrated from mackerel tissues were used to synthesize triglycerides by lipase-catalyzed esterification. The effect of temperature, reaction medium, enzyme, moisture removal system and glycerol to fatty acid ratio on extent of synthesis were investigated. The synthesis process was also optimized using central composite design to determine the best conditions for high synthesis yield. The fatty acid composition and positional analyses were determined by GC-FID and electrospray ionization mass spectrometry (EI-MS)
The results showed that mackerel skins were most suitable for concentrating PUFA. The eicosapentaenoic acid (EPA) and -docosahexaenoic acid (DHA) content of fish oil from the tissues examined ranged between 6.3--9.7 (wt%) with an iodine value of 134 +/- 5.0. The baseline total PUFA content was increased from ca 21.0 to ca 83.0 (wt%) with an associated iodine value of 296 +/- 7.0 using urea complexation. Low (50 ppm and 100 ppm) levels of alpha-tocopherol in combination with low storage temperature (-40°C) showed lowest oxidation after 66 days of storage. High levels (250 and 500 ppm) of alpha-tocopherol were observed to be prooxidant based on TBARS, peroxide and conjugated diene measurements. Urea to fatty acid ratio and temperature were predominant effectors influencing the amounts of individual omega-3 fatty acids and total PUFA concentrated by urea complexation. The model developed for the optimized urea complexation process were capable of predicting the yields of EPA, DHA, total PUFA and Iodine values to a high degree of accuracy at R2 = 0.87, 0.96, 0.95, and 0.92 respectively.
Sunflower oil was most suitable for synthesizing conjugated linoleic acid by alkaline isomerization, compared with soybean, canola and corn oil. Two CLA isomers, c9,t11 and t10, c12 were most abundant and occurred in approximately equal proportions irrespective of vegetable oil used. Total CLA synthesized from sunflower oil was 93.5 +/- 3.5 (wt%) with the two major isomers making up 89 +/- 3.5 (wt%). Candida antartica lipase showed more synthesis activity than Mucor meihie in both organic and solvent-free systems. Analysis of isolated synthesized triglycerides by GC-FID and mass spectrometry showed that DHA, EPA, CLA and linolenic acid were the main fatty acids incorporated into the triglycerides. DHA and EPA were mostly esterified at the sn-2 position.
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Castagnino, Pablo de Souza. "In vitro fermentation parameters and biohydrogenation of vegetable oils without glycerol /". Jaboticabal, 2014. http://hdl.handle.net/11449/113760.
Testo completoAbstract (sommario):
Orientador: Telma Teresinha BerchielliCoorientador: Juliana Duarte Messana
Banca: Izabelle Auxiliadora Molina de Almeida Teixeira
Banca: Paulo Henrique Moura Dian
Resumo: O glicerol combinado com óleos vegetais poderia limitar a intensa biohidrogenação dos ácidos graxos de cadeia longa e a produção de metano sem causar efeitos deletérios sobre a população microbiana e digestibilidade. Três incubações in vitro foram conduzidas para avaliar o efeito do glicerol (0 or 150 g/kg MS) combinado com três diferentes dietas: Feno de Tifton 85 sem a inclusão de óleo (FSO), Feno de Tifton 85 + 80g de óleo de soja/kg MS (FOS) e Feno de Tifton 85 + 80 g de óleo de linhaça/kg MS (FOL) incubados por 0, 6, 12 e 24 h sobre a composição de ácidos graxos e os parâmetros de fermentação ruminal. A PCR em tempo-real (qPCR) foi utilizado para quantificação de microorganismos às 24 h. As arquéias metanogênicas ,bactérias celulolíticas e lipolíticas foram expressas em função das bactérias totais. Separadamente, a cinética de produção de gases foi avaliada nos tempos 2, 4, 6, 8, 10, 12, 14, 18, 22, 24, 36, 42 e 48 h. A digestibilidade verdadeira in vitro (DVIV) e a produção CH4 (%/g DMS) foram avaliadas às 48 h. Os valores de pH e as concentrações de amônia (NH3-N) foram menores nas dietas FSO comparado com FOS e FOL, independente da adição de glicerol (P<0,05). A proporção da Anaerovibrio lipolytica aumentou 84, 33 e 13 vezes nas dietas FSO, FOS e FOL com adição de glicerol, respectivamente, comparadas com as dietas sem glicerol (P<0,05). Ruminococcus albus, Ruminococcus flavefaciens e os subgrupos Butyrivrio VA e SA subgroup não foram alteradas com a inclusão dos óleos vegetais e de glicerol (P>0,05). As bactérias Fibrobacter succinogenes foram mais sensíveis a adição de óleos vegetais entre todas as bactérias celulolíticas (P<0,05). A DVIV e a produção de CH4 foram inferiores nas dietas FOS com adição de glicerol e na dieta FOL independente da adição de glicerol (P<0,05). A redução na produção de gases ocorreu nas dietas FOS e FOL associadas com glicerol ...
Abstract: Glycerol combined with vegetable oils could limit biohydrogenation and enhance the reduction in methane production without depressing digestibility and microbial population. Three in vitro incubations were conducted to evaluate the effect of glycerol (0 or 150 g/kg DM) combined with three different diets: Tifton 85 hay without oil seeds (HWO), Tifton 85 hay + 80g of soybean oil/kg DM (HSO) and Tifton 85 hay + 80 g of linseed oil/kg DM (HLO) incubated for 0, 6, 12 and 24 h on fatty acid composition and ruminal fermentation parameters. Real-time PCR was used to quantify microbial population at 24 h. Methanogens, fibrolitic and lipolityc bacteria were expressed as a proportion of total rumen bacterial 16 S rDNA. Separately, kinetic of gas production was assessed at 2, 4, 6, 8, 10, 12, 14, 18, 22, 24, 36, 42 and 48 h. In vitro true digestibility (IVTD) and CH4 (%/g DMD) production were evaluated at 48 h. The experimental design for fatty acid composition and ruminal parameters was a randomized block in a factorial arrangement 2 x 3 x 4, involving the following factors: glycerol (2), diets (3) and time (4). Microbial quantification, IVTD and CH4 were evaluated with the same design but without time as a factor. The pH value and ammonia (NH3-N) concentration were lower in HWO compared with HSO and HLO diets, regardless of glycerol addition (P<0.05). Anaerovibrio lipolytica proportion increased 84, 33 and 13 times in HWO, HSO and HLO diets with glycerol, respectively, compared with diets without glycerol (P<0.05). Ruminococcus albus, Ruminococcus flavefaciens and Butyrivrio VA and SA subgroup did not change with glycerol and oil addition (P>0.05). Among all cellulolytic bacteria, Fibrobacter succinogenes was the most sensitive to the addition of vegetable oil in the diet (P<0.05). CH4 production decreased in HSO diet associated with glycerol and HLO diets with or without glycerol addition (P<0.05). Lag time decreased in HWO and HSO diets ...
Mestre
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Ginsburg, Shoshana Rivka. "Extraction of Lipid Soluble Antioxidants from Rosemary Leaves Using Vegetable Oils". The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1563290049617458.
Testo completo
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Satyarthi, J. K. "Catalytic conversion of vegetable oils to biofuels over transition metal catalysts". Thesis(Ph.D.), CSIR-National Chemical Laboratory, Pune, 2011. http://dspace.ncl.res.in:8080/xmlui/handle/20.500.12252/3772.
Testo completo
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Gibert, Casamada Anna. "The utilization of filled milk in the manufacture of yogurt". Thesis, University of Lincoln, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.262208.
Testo completo
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Kalu, Clara U. U. "A chemical and organoleptic assessment of autoxidising oils". Thesis, Liverpool John Moores University, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.262066.
Testo completo
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Prokkola, H. (Hanna). "Biodegradation studies of recycled vegetable oils, surface-active agents, and condensing wastewaters". Doctoral thesis, Oulun yliopisto, 2015. http://urn.fi/urn:isbn:9789526209869.
Testo completoAbstract (sommario):
Abstract Biodegradation is an aerobic or anaerobic degradation reaction where bacteria use organic materials as an energy source. In the aerobic biodegradation reaction, bacteria need oxygen as an electron acceptor, whereas an anaerobic reaction takes place in the absence of oxygen. Compounds degrade totally or partially, and produce simple inorganic species, such as CO2, CH4, NH3, NO3−, and H2O, as well as by-products that may be non-biodegradable and/or toxic. In this thesis, the biodegradability of recycled vegetable oils, surface-active agents, and condensing waters from the process of wood drying were studied using the manometric respirometric BOD OxiTop method. The biodegradation of organic compounds was measured under the standard conditions (OECD 301F), and also in other matrices, such as different waters and soils. These are very different environments with respect to the biodegradation reaction in nature. The main differences in waters and soils are their organic and inorganic nutrient contents, bacteria strains, and temperatures. The BOD OxiTop method is based on automatic pressure detection in a closed reactor vessel. Oxygen is consumed and carbon dioxide is formed in the aerobic reaction. The pressure decrease is detected after the carbon dioxide is adsorbed into a NaOH pellet or solution. The pressure change is dependent on oxygen consumption. The degree of biodegradation is calculated from the BOD value of the sample. The studied recycled vegetable oils were found to be 60–83% biodegradable, and the added surface-active agent did not affect their biodegradation. Biodegradation of tall oil soaps was also examined in sand, topsoil, groundwater, and surface water, as well as under OECD 301F standard conditions. Tall oil soaps were proven to be 50–85% biodegradable. Concrete solvent agent (CSA) was also proven to be 78–83% biodegradable under standard conditions. Another detergent, cetyltrimethylammonium bromide (CTAB), was found to be toxic, whereas Triton X-100 biodegraded by only 6% in solution. Biodegradation of the soil matrix was found to be enhanced with added surface-active agents. This can be explained by better wetting of small pores with surface-active agents, as compared to the behavior of pure water. The biodegradation of the matrix occurred even with toxic surface-active agents. Organic pollutants of wastewaters from the process of wood drying were 25–61% biodegradable during a 28-day period, and were proven to be quite pure when considering the carbon content of the samples. Based on these results, the disposal into drainage of condensing waters from wood drying may be regarded as safe, which from an economical viewpoint is a very important conclusionTiivistelmä Biohajoavuus on luonnollinen aerobinen tai anaerobinen hajoamisprosessi, jossa bakteerit käyttävät orgaanista materiaalia energian lähteenä. Aerobisessa reaktiossa bakteerit tarvitsevat happea elektronien vastaanottajaksi, kun taas anaerobinen reaktio tapahtuu hapettomissa olosuhteissa. Yhdisteet hajoavat joko täysin tai osittain sekä tuottavat yksinkertaisia epäorgaanisia yhdisteitä, kuten CO2, CH4, NH3, NO3− tai H2O. Reaktiossa voi myös muodostua sivutuotteita, jotka voivat olla biohajoamattomia ja/tai toksisia. Tässä työssä on tutkittu kierrätettyjen kasviöljyjen, pinta-aktiivisten aineiden sekä jätevesien sisältämien orgaanisen aineksien biohajoavuuksia käyttäen manometristä respirometristä BOD OxiTop-menetelmää. Biohajoavuutta mitattiin standardiolosuhteiden (OECD 301F) lisäksi muissakin olosuhteissa, kuten erilaisissa maissa ja vesissä. Nämä ovat kaikki hyvin erilaisia ympäristöjä luonnossa tapahtuville biohajoavuusreaktioille. Pääasialliset erot ovat sekä orgaanisten että epäorgaanisten ravinteiden määrässä, bakteerikannoissa ja lämpötilassa. BOD OxiTop-menetelmä perustuu automaattiseen paineen muutoksen havainnointiin suljetussa astiassa. Aerobisessa reaktiossa kuluu happea ja muodostuu hiilidioksidia, joka imeytetään NaOH-pelletteihin tai -liuokseen ja tästä muodostuu alipaine. Paineen muutokset muunnetaan hapenkulutuksen arvoiksi, joista lasketaan biohajoavuusaste. Tutkittujen kierrätettyjen kasviöljyjen biohajoavuusasteet vaihtelivat välillä 60–83 %, eikä lisätty pinta-aktiivinen aine vaikuttanut kyseisten ekoöljyjen biohajoavuuteen. Mäntysaippuoiden biohajoavuus tutkittiin standardiolosuhteiden lisäksi hiekassa, mullassa, pohjavedessä sekä pintavedessä. Niiden biohajoavuusasteet vaihtelivat välillä 50–85 %. Betoninpesuaineen biohajoavuusaste standardiolosuhteissa oli 78–83 %. Kahdesta tutkituista pinta-aktiivisista aineista setrimoniumbromidi (CTAB) oli myrkyllinen liuosolosuhteissa eikä täten biohajonnut ja Triton X-100 biohajosi vain 6 %. Pinta-aktiivisen aineen lisääminen maahan aiheutti matriisina käytetyn maan biohajoamisen. Tämä voitiin selittää siten, että pintajännityksen laskemisen jälkeen neste voi paremmin tunkeutua maan pieniin huokosiin ja näin tuoda hajoamatonta orgaanista ainesta ja uusia bakteereita biohajoavuuskäyttöön. Tämä ilmiö havaittiin myös myrkyllisen pinta-aktiivisen aineen lisäyksen jälkeen. Jätevesien sisältämät orgaaniset ainekset hajosivat 25–61 % 28 päivän aikana ja niiden havaittiin olevan hiilen määrän huomioon ottaen hyvin puhtaita. Tässä tutkimuksessa saatujen tulosten perusteella tutkitut puunkuivauksen kondenssivedet voidaan laskea viemäriin, mikä on erittäin tärkeä tulos ekologiselta ja taloudelliselta kannalta katsottuna
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O'Neill, Alfred John. "The extraction of vegetable oils from potato chips using supercritical carbon dioxide". Thesis, University of Ottawa (Canada), 1987. http://hdl.handle.net/10393/5194.
Testo completo
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Rodrigues, Ângela. "Chemical modification of vegetable oils to improve oxidative resistance and physical properties". Thesis, Manchester Metropolitan University, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.501958.
Testo completoAbstract (sommario):
This thesis investigates the acetylation of the unsaturated groups present in the hydrocarbon chain of rapeseed oil and esterification of the hydroxyl groups present in hydrogenated castor oil. The reaction of carboxylic acids, acetic anhydride and acid chlorides with the hydroxyl group of solid hydrogenated castor oil is explored to instigate a change in the physical properties. Such modifications often change the solid, lard-like material, into a liquid with potential for use as a dielectric fluid. The reaction of hydrogenated castor oil with acetic acid and sulphuric acid or PTSA as catalysts, results in 98% yield for esterification of the hydroxyl group after only 2 hours reaction at 120 °C. At this point, there is evidence that unsaturation in the chains of the ricinoleic acid starts to appear.
25
Retief, Liezel. "Analysis of vegetable oils, seeds and beans by TGA and NMR spectroscopy". Thesis, Stellenbosch : University of Stellenbosch, 2011. http://hdl.handle.net/10019.1/6831.
Testo completoAbstract (sommario):
Thesis (PhD (Chemistry and Polymer Science))--University of Stellenbosch, 2011.ENGLISH ABSTRACT: Due to the commercial, nutritional and health value of vegetable oils, seeds and beans, the analysis of their components is of much interest. In this dissertation oil-containing food products, specifically vegetable oils, seeds and beans, were investigated. Selected minor components of three locally produced vegetable oils, namely apricot kernel, avocado pear and macadamia nut oils were investigated using 31P NMR spectroscopy. These minor components, including 1,2 diacylglycerols, 1,3 diacylglycerols and free fatty acids, were identified in the 31P NMR spectra of each of the three vegetable oils for the first time. Two approaches were used for the quantification of the minor components present in the spectra. A calibration curve approach used known concentrations of standard minor components to establish calibration curves while a direct correlation approach calculated the unknown concentration of minor components in the vegetable oils using a known amount of standard compound within the analysis solution. These approaches aided in determining the concentration of minor components during storage studies in which vegetable oils were stored in five different ways: exposed to light, in a cupboard, in a cupboard wrapped in tin foil, at -8 °C and at 5 °C. It was found that determining the best storage condition for each oil was difficult since individual minor components were affected differently by the various storage conditions. However, in general the best storage conditions appeared to be 5 °C and -8 °C. The oil, protein and carbohydrate contents of sesame, sunflower, poppy, and pumpkin seeds, and soy, mung, black and kidney beans were analysed by thermogravimetric analysis and 13C NMR solid state NMR spectroscopy. It was shown that the first derivative of TGA data for seeds and beans can give valuable information about the carbohydrate, moisture, protein and fat content. This has not been previously demonstrated. For the seeds, the integration of a region between 270–480 ºC was equal to the sum of the oil and protein content and compared well to quantitative results obtained by other conventional methods. For beans the integration of a region between 180-590 ºC, gave a value which represented the sum of the oil, protein and carbohydrate content. 13C solid state NMR spectroscopy, including SPE-MAS, CP-MAS and variable contact time experiments, was carried out on these seeds and beans and gave valuable information on the solid-like and liquid-like components. To our knowledge these seeds and beans have never been previously analysed using this technique. 13C SPE-MAS NMR spectroscopy indicated that the seeds contained more liquid-like components than the beans. In turn the 13C CP-MAS NMR spectra indicated that beans had higher levels of solid-like components than the seeds. These conclusions correlated well with the quantities of liquid-like components and solid-like components that were determined by conventional methods and TGA. Preliminary studies using T1pH experiments on the components present in the seeds and beans led to a few observations. Most interesting is that a model using a two- phase fit in order to determine T1pH values appears to be more accurate than a one-phase model.
AFRIKAANSE OPSOMMING: Groente olies, sade en bone is ‘n onderwerp van groot belang omrede hul kommersiële, voeding en gesondheidswaardes. In hierdie tesis is olie-bevattende voedselprodukte, spesifiek groente-olies, sade en bone geanaliseer. Geselekteerde komponente teenwoordig in klein hoeveelhede in drie lokaal geproduseerde groente-olies, naamlik appelkoos-pit, avokadopeer en makadamia-neut olies is geanaliseer met behulp van 31P KMR spektroskopie. Hierdie komponente, insluitend 1,2 diasielglyserole, 1,3 diasielglyserole en ongebonde vetsure, is vir die eerste keer geïdentifiseer in die 31P KMR spektra van die drie groente olies. Twee benaderings is gebruik vir die hoeveelheids-bepaling van die komponente in die spektra. ‘n Yking-kurwe metode het gebruik gemaak van bekende hoeveelhede konsentrasies standaard komponente vir die opstel van yking-kurwes, terwyl ‘n direkte korrelasie metode gebruik is om die onbekende konsentrasie van komponente in groente olies te bepaal met behulp van ‘n bekende hoeveelheid standaard verbinding teenwoordig in die oplossing. Hierdie metodes het gelei tot die bepaling van die konsentrasies van die komponente gedurende vyf verskillende berging toestande wat ingesluit het: Blootgestel aan lig, in ‘n donker kas, in ‘n donker kas toegevou in tin foelie, bevries by -8 °C en in ’n koelkas by 5 °C. Dit was bevind dat bepaling van die beste bergingstoestand vir elke olie moeilik is aangesien die individuele komponente verskillend geaffekteer word deur die verskeie berging toestande. Die beste bergings toestand oor die algemeen blyk egter om by 5 °C en -8 °C te wees. Sesamsaad, sonneblomsaad, papawersaad en pampoensaad sowel as sojaboontjie, mungboontjie, swartboontjie en pronkboontjie se olie, protein en koolhidraat komponente was geanaliseer met behulp van termogravimetriese analise (TGA) en 13C soliede toestand KMR spektroskopie. Dit was bevind dat die eerste afgeleide van die TGA data waardevolle inligting lewer oor die komponent inhoud van elk van die sade en bone. Hierdie is nog nie vantevore bevind nie. Vir die sade, was die integrasie van ‘n area tussen 270–480 ºC gelyk aan die som van die olie en proteïen inhoud en het goed vergelyk met die waardes verky deur algemene analitiese metodes. Vir die boontjies, was die integrasie van ‘n area tussen 180-590 ºC gelyk aan die som van die olie, protein en koolhidraat inhoud. 13C vaste staat KMR spektroskopie, insluitende SPE-MAS, CP-MAS en variëerbare kontak-tyd eksperimente, was gedoen en het waardevolle inligting gelewer omtrent die solied-agtige en mobiel-agtige komponente. Hierdie sade en bone is tot ons kennis nog nie van te vore met die tegnieke ondersoek nie. 13C SPE-MAS NMR spektroskopie het aangedui dat daar ‘n groter hoeveelheid mobiel-agtige komponente in sade as in bone teenwoordig is. 13C CP-MAS NMR spektroskopie het weer aangedui dat daar ‘n groter hoeveelheid solied-agtige komponente in bone as in sade teenwoordig is. Hierdie gevolgtrekkings het goed vergelyk met die waarnemings verkry deur konvensionele analitiese metodes en TGA. Voorlopige studies op die komponente van sade en bone deur T1pH eksperimente het tot ‘n paar gevolgtrekkings gelei waarvan die mees interessantste was dat ‘n twee-fase model vir die bepaling van T1pH waardes beter resultate lewer as ‘n een-fase model.
26
Panchal, B. "Production of polyhydroxyalkanoates by Pseudomonas mendocina using vegetable oils and their characterisation". Thesis, University of Westminster, 2016. https://westminsterresearch.westminster.ac.uk/item/9x22w/production-of-polyhydroxyalkanoates-by-pseudomonas-mendocina-using-vegetable-oils-and-their-characterisation.
Testo completoAbstract (sommario):
Synthesis of Polyhydroxyalkanoates (PHAs) by Pseudomonas mendocina, using different vegetable oils such as, coconut oil, groundnut oil, corn oil and olive oil, as the sole carbon source was investigated for the first time. The PHA yield obtained was compared with that obtained during the production of PHAs using sodium octanoate as the sole carbon source. The fermentation profiles at shaken flask and bioreactor levels revealed that vegetable oils supported the growth of Pseudomonas mendocina and PHA accumulation in this organism. Moreover, when vegetable oil (coconut oil) was used as the sole carbon source, fermentation profiles showed better growth and polymer production as compared to conditions when sodium octanoate was used as the carbon source. In addition, comparison of PHA accumulation at shaken flask and fermenter level confirmed the higher PHA yield at shaken flask level production. The highest cell mass found using sodium octanoate was 1.8 g/L, whereas cell mass as high as 5.1 g/L was observed when coconut oil was used as the feedstock at flask level production. Moreover, the maximum PHA yield of 60.5% dry cell weight (dcw) was achieved at shaken flask level using coconut oil as compared to the PHA yield of 35.1% dcw obtained using sodium octanoate as the sole carbon source. Characterisations of the chemical, physical, mechanical, surface and biocompatibility properties of the polymers produced have been carried out by performing different analyses as described in the second chapter of this study. Chemical analysis using GC and FTIR investigations showed medium chain length (MCL) PHA production in all conditions. GC-MS analysis revealed a unique terpolymer production, containing 3-hydroxyoctanoic acid, 3-hydroxydecanoic acid and 3-hydroxydodecanoic acid when coconut oil, groundnut oil, olive oil, and corn oil were used as the carbon source. Whereas production of the homopolymer containing 3-hydroxyoctanoic acid was observed when sodium octanoate was used as the carbon source. MCL-PHAs produced in this study using sodium octanoate, coconut oil, and olive oil exhibited melting transitions, indicating that each of the PHA was crystalline or semi-crystalline polymer. In contrast, the thermal properties of PHAs produced from groundnut and corn oils showed no melting transition, indicating that they were completely amorphous or semi-crystalline, which was also confirmed by the X-Ray Diffraction (XRD) results obtained in this study. Mechanical analysis of the polymers produced showed higher stiffness of the polymer produced from coconut oil than the polymer from sodium octanoate. Surface characterisation of the polymers using Scanning Electron Microscopy (SEM) revealed a rough surface topography and surface contact angle measurement revealed their hydrophobic nature. Moreover, to investigate the potential applicability of the produced polymers as the scaffold materials for dental pulp regeneration, multipotent human Mesenchymal stem cells (hMSCs) were cultured onto the polymer films. Results indicated that these polymers are not cytotoxic towards the hMSCs and could support their attachment and proliferation. Highest cell growth was observed on the polymer samples produced from corn oil, followed by the polymer produced using coconut oil. In conclusion, this work established, for the first time, that vegetable oils are a good economical source of carbon for production of MCL-PHA copolymers effectively by Pseudomonas mendocina. Moreover, biocompatibility studies suggest that the produced polymers may have potential for dental tissue engineering application.
27
Cash, Gregory Anthony. "Studies of the oxidation and stabilisation of vegetable oils and model compounds". Thesis, Queensland University of Technology, 1986. https://eprints.qut.edu.au/35985/1/35985_Cash_1986.pdf.
Testo completoAbstract (sommario):
This thesis describes the use of a novel chemiluminescence (CL)
technique to deter·mine the extent of oxidation and stability in
both model compounds and vegetable oils. As it is the presence
of hydroperoxides in vegetable oils that leads to theirdeterioration,
the hydroperoxides of methyl linoleate (MU were
used as model compounds in a CL study of hydroperoxide
decomposition in nitrogen, both in the bulk and on active
substrates. The largest signals and the fastest decays
occurred on neutral alumina. The results indicate induced
decomposition via a bimolecular initiation of hydroperoxides
adsorbed on adjacent active sites. The majority of these
hydroperoxides are vertical to the surface, being bound to the
alumina through the ester group only.
A relationship was found between hydroperoxide concentr·ation
and initial intensity when the methyl linoleate hydroperoxide
was adsorbed on neutral alumina. Solutions of natural and
arti-ficial antioxidants in ML were studied. Some solutions
gave changes in kinetics. These changes suggest that the
antioxidant itself may contribute to the CL. The method of
inhibitors was used to find the rate of initiation and
hydroperoxide level in ML at 80c:>C.
The spectral distribution of CL was determined for model
compounds, antioxidants and vegetable oils. In the presence of
antioxidants ther-e was a shift towar-d the r-ed end of the
spectr-um. In model compounds, the CL was most likely due to an
excited triplet state ketone and this is consistent with the
mechanism for- ter·mination of alkyl peroxy r-adicals.
The techniques developed for the model compounds were extended
to the mor-e complex vegetable oils. Unrefined and deliberately
damaged vegetable oils were studied at 80c:>C on neutral
alumina. CL examination of these oils in nitr-ogen was able to distinguish between some damaged and undamaged oils.
Conjugated diene levels did not correlate well with CL results.
0<-tocopherol and a-carotene were found to be chemiluminescent
on alumina and their presence in unr·efined oil may inter·fer·e
with CL assessment.
The method of inhibitors, when applied to a vegetable oil
sample, permitted the determination of both hydroperoxide
concentration and the level of natural antioxidant alr-eady
present in the oil.
ii
28
Ares, Gondra Zaloa. "Study of factors influcencing the quality and yield of biodiesel produced by transesterification of vegetable oils". Thesis, University of Gävle, Faculty of Engineering and Sustainable Development, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-6934.
Testo completoAbstract (sommario):
Biofuels are a developing kind of fuel whose origin is biomass. Among them, many different kind of fuels can be found: bioethanol, biobutanol, biodiesel, vegetable oils, biomethanol, pyrolysis oils, biogas, and biohydrogen. This thesis work is focused on the production of biodiesel, which can be used in diesel engines as a substitute for mineral diesel. Biodiesel is obtained from different kinds of oils, both from vegetable and animal sources. However, vegetable oils are preferred because they tend to be liquid at room temperature.
The process to obtain biodiesel implies first a reaction between the oil and an alcohol, using a catalyst and then a sedimentation, where the biodiesel and the glycerol, the two products that are obtained, can be separated because of their difference in density. After the separation, raw biodiesel is obtained and a treatment with either water bubbling or dry cleaning products is needed to obtain the product which will be ready to use.
Many methods are available for the production of biodiesel, most of them require heat for the transesterification reaction, which converts the oil into biodiesel. Apart from that, in many cases biodiesel is produced by big companies or by individuals but using complicated and expensive installations.
This work is an attempt to develop a way of producing biodiesel without any use of external heat, using a simple procedure which could be used by people with a low knowledge of chemistry or chemical processes. It also seeks to set an example on how biodiesel can be easily made by oneself without the use of any industrial systems, with a low budget and limited need of supervision over the process.
In order to achieve that, many trials were undertaken, introducing changes in the different parameters that are responsible for the changes in the final product. Among them, changes in the amount and type of catalyst, the way the catalyst is added, the type of oil used, the time of reaction and the temperature were made. Apart from that, different types of cleaning were tried, starting by water cleaning and then using powder type products, Magnesol, D-Sol and Aerogel. A centrifuge was also tried to test its utility when separating impurities from liquids or different liquid phases. The results of the different trials were analysed using various tests, the most important being the 3:27 test, the solubility test, the soap titration and pH measurements.
To sum up, it could be said that the investigation was a success, since it was proved that biodiesel can be made without the use of any external heat with both alkali and acid catalysts, as well as with different ways of adding the catalyst. As for the cleaning, good results were obtained with both dry products and water cleaning, since the soap content of the biodiesel was reduced in both cases. Apart from that, the centrifuge proved to be valid to eliminate impurities from raw oil.
29
Zhu, Lin. "Development of elastomers and elastomeric nanocomposites from plant oils". Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 275 p, 2006. http://proquest.umi.com/pqdweb?did=1068271741&sid=6&Fmt=2&clientId=8331&RQT=309&VName=PQD.
Testo completo
30
Gersbach, Paul Vincent, University of Western Sydney e of Science Technology and Environment College. "Aspects of essential oil secretion in vascular plants". THESIS_CSTE_XXX_Gersbach_P.xml, 2001. http://handle.uws.edu.au:8081/1959.7/775.
Testo completoAbstract (sommario):
A study of some aspects of essential oil secretion in plants was conducted. The first part of the study involved analysis of the volatile terpenoid content and composition of leaf extracts from a range of Australian native plants by gas chromatography and mass spectrometry. Secretory structures were studied by several microscopic imaging techniques including conventional bright and dark field optical microscopy, confocal microscopy, and scanning (SEM) and transmission (TEM) electron microscopy. Three methods were employed for scanning electron microscopy. Sample material was prepared for conventional SEM by chemical fixation and rapid freeze fixation, and fresh material was imaged by environmental SEM. These methods were compared, and the images acquired by environmental SEM were invariably of a superior standard as the biological integrity of the samples was retained throughout, and the samples were free of process-induced artefacts. Several other tests were conducted and results discussed in some detail. In the final part of the study, aspects of essential oil secretion were examined by histochemical methods. The first of these was a new method based on traditional approaches to histochemistry. The monoterpene phenols thymol and carvacrol were located in glandular trichomes of Lamiaceae species by means of a colour-change reaction of the phenols with a nitrosophenol/acid reagent. The second used magnetic resonance imaging by a chemical shift selective method to locate, non invasively, the aromatic monoterpenes thymol and anethole in secretory structures in the fruit of Carum copticum (Apiaceae) and the leaves of Backhousia anisata (Myrtaceae) respectively.Doctor of Philosophy (PhD) (Science)
31
Cai, Xiaoshuang. "Production of carbonated vegetable oils from a kinetic modeling to a structure-reactivity approach Structure-reactivity : comparison between the carbonation of epoxidized vegetable oils and the corresponding epoxidized fatty acid methyl ester Aminolysis of cyclic-carbonate vegetable oils as a non-isocyanate route for the synthesis of polyurethane: a kinetic and thermal study Influence of ring‐opening reactions on the kinetics of cottonseed oil epoxidation Investigation of the physicochemical properties for vegetable oils and their epoxidized and carbonated derivatives Influence of gas-liquid mass transfer on kinetic modeling : carbonation of epoxidized vegetable oils". Thesis, Normandie, 2019. http://www.theses.fr/2019NORMIR05.
Testo completoAbstract (sommario):
La valorisation de la biomasse et du dioxyde de carbone est à présent considérée comme une solution aux problèmes environnementaux du réchauffement climatique et l'épuisement des réserves de pétrole. Ainsi, les huiles végétales ont attiré l'attention croissante des milieux universitaires et industriels, comme une source de biomasse potentielle renouvelable qui peut être appliquée à la production de substitut fossile pour un développement durable, due à leurs caractères renouvelables, durables, biodégradables. De plus, cette biomasse est disponible avec une énorme quantité. Durant des décennies de recherches, les processus d'époxydation et de carbonatation sont deux méthodes d'application populaires pour la valorisation des huiles végétales. La conversion des huiles végétales en huiles époxydées est définie par une conversion d'un composé insaturé en un groupe époxyde. Jusqu'ici, l'oxydation de Prileschajew est la méthode de synthèse plus efficace pour la possible industrialisation du processus d'époxydation de huiles végétales, qui est une manière conventionnelle bien connue à utiliser comme processus de production commerciale. Ce type d'époxydation utilise l'acide percarboxylique comme transporteur d'oxygène qui est formé in situ dans la phase aqueuse, et ensuite époxyde les groupes insaturés des huiles végétales en groupes époxyde. Cependant, cette méthode présente une réaction secondaire d'ouverture du cycle du groupe époxyde au cours du processus. Donc, les conditions du procédé d'époxydation doivent être optimisées afin de minimiser les réactions d'ouverture de cycle. Des paramètres de réaction, y compris la concentration en catalyseur acide (acide sulfurique), réactifs (eau, groupe époxyde, peroxyde d'hydrogène, acide acétique) et la température de réaction, ont été discutés dans cette étude pour l'époxydation et réaction d'ouverture de cycle des huiles végétales. Au cours de la modélisation cinétique, les constantes cinétiques associées pour les réactions d'ouverture du cycle ont été estimées. En se basant sur ce modèle, les réactions d'ouverture du cycle époxyde par les acides acétique et peracétique sont plus rapides que celles de l'eau et du peroxyde d'hydrogène. Un réacteur en mode semi-fermé, avec addition du peroxyde d'hydrogène et de l'acide sulfurique, est la configuration la plus appropriée pour la production d'huiles végétales époxydées. Pour déterminer les conditions optimales et passer à échelle industrielle dans les procédés d'époxydation et de la carbonation, il faut connaître différentes propriétés physicochimiques telles que la viscosité, la densité, l'indice de réfraction, la capacité thermique spécifique et les évolutions de ces données avec la température. Cependant, aucune information sur ces propriétés est disponible dans la littérature. Pour cette étude, l'évolution de ces propriétés ont été déterminées pour trois huiles végétales et leurs dérivés époxydées et carbonates (l'huile de coton, l'huile de lin et l'huile de soja) avec la température et leur composition. La densité et l'indice de réfraction ont été trouvé linéairement dépendant de la température pour les huiles étudiées. La relation entre la contrainte de cisaillement et le taux de cisaillement dans l’étude de viscosité, indique que ces huiles sont des fluides newtoniens. Il a été démontré que la capacité thermique spécifique suit une équation polynomiale du second ordre avec la température. Sur la base de ces résultats, il a été démontré que certaines corrélations pourraient être utilisées pour prédire les évolutions de ces propriétés physicochimiques à différentes compositions et températuresNowadays, biomass and carbon dioxide valorization are considered as a helpful solution to the environmental issues of global warming and the depletion of petroleum reserves. Thus, vegetable oils have attracted increasing attention of academic and industrial communities, as one of the potential renewable biomass that can be applied to the production of fossil substitute for sustainable development, owning to their advantages of renewable, sustainable, biodegradable, and universally available with huge feedstock. Among decades of researches, epoxidation and carbonation processes are two popular application methods for vegetable oil valorization. The conversion of vegetable oils into epoxidized ones is defined by a conversion of unsaturated compound into an epoxide group. So far, the potential application for the production of epoxidized oil in the industrial is the Prileschajew oxidation, which is a wellknown conventional way to be used as the commercial production process. This type of epoxidation uses percarboxylic acid as an oxygen carrier, which is formed in situ in the aqueous phase, and then epoxidize the unsaturated groups on the vegetable oils into epoxide groups. During the process, however, this method presents side reaction of ring-opening of the epoxide group. Therefore, the selective epoxidation process conditions need to be optimized in order to minimize the ring-opening reactions. In this study, process parameters including the concentration of acid catalyst (sulfuric acid), reactants (water, epoxide group, hydrogen peroxide, acetic acid) and the reaction temperature have been discussed for the epoxidation and ring opening of vegetable oils. During the kinetic modeling stage, the related kinetic constants for the ring opening reactions were estimated. Based on this model, the ring opening by acetic and peracetic acids was found to be faster than by water and hydrogen peroxide. A semibatch reactor, where hydrogen peroxide and sulfuric acid were added, was found to be the most suitable configuration. To determine the optimum operating conditions and scale up the epoxidation or carbonation processes, it requires the database of different physicochemical properties, i.e. viscosity, density, refractive index, or specific heat capacity and the evolutions of these properties with the temperature. However, this information is absent in the literature. For this study, the evolution of these properties with temperature and compositions (double bond, epoxide and carbonated groups concentration) was determined for three vegetable oils and their corresponding epoxidized and carbonated forms (cottonseed oil, linseed oil and soybean oil). Density and refractive indices of these oils were found to vary linearly with temperature. Based on the measurement of changes in viscous stresses with shear rates, these oils were found to be Newtonian fluids. It was demonstrated that specific heat capacity follows a polynomial equation of second order with temperature. Based on these results, it was demonstrated that some correlations could be used to predict the evolutions of these physicochemical properties at different composition and temperature based on the knowledge of the property of the pure compounds
32
Kim, Kyunghoon [Verfasser]. "Epoxidation of vegetable oils using the heterogeneous catalysis, amorphous Ti-SiO2 / Kyunghoon Kim". Aachen : Hochschulbibliothek der Rheinisch-Westfälischen Technischen Hochschule Aachen, 2012. http://d-nb.info/1023931931/34.
Testo completo
33
Bahari, Adli. "Investigation into tribological performance of vegetable oils as biolubricants at severe contact conditions". Thesis, University of Sheffield, 2017. http://etheses.whiterose.ac.uk/19524/.
Testo completoAbstract (sommario):
The concern about the pollution created by the use of mineral oil based lubricants and the depletion stock of petroleum has inspired research on alternative lubricants known as biolubricants. The tribological performance of vegetable oils (palm oil and soybean oil) as biolubricants and their blends with mineral oil and anti-wear additives was evaluated in order to assess their potential use in automotive engines. The tests were performed using a reciprocating ball-on-flat test-rig at severe contact conditions with grey cast iron specimens. The performance was compared with a commercial mineral engine oil for benchmarking purposes. At severe contact conditions, the friction and wear results of vegetable oil lubricants were found to be greatly influenced by the wide hardness range of the grey cast iron specimens. The measurement of hardness on the intended wear scar region prior to testing was used in order to provide more robust tribological data. In a pure oil state, the palm oil performance was found to be competitive in friction coefficient with mineral engine oil. However, the mineral oil is far superior in wear protection over vegetable oils due to the additive package it contains its superior oxidative stability. For a vegetable oil-mineral oil blend in equal ratio, the reduction of friction and wear was not significant. However, the addition of 2% zinc dialkyl dithiophosphate in vegetable oils gave significant improvement on the friction and wear. The friction coefficient of palm oil with this additive was very close to the commercial mineral engine oil. The zinc dialkyl dithiophospate in vegetable oil was found to perform three functions; as an anti-wear agent, anti-oxidant and friction modifier. The blend of vegetable oils with boron nitride, however, did not give better results. This could be mainly due to the selection of particles size which was not suitable with the surface roughness. When putting all the results together, the downside of pure vegetable oils is found to be greater in terms of wear resistance and oxidative stability compared to friction. This effect was prominent when they were blended with mineral oils where their tribological performance dominated. However, with the commercial anti-wear additive, specifically the zinc dialkyl dithiophosphate, the vegetable oils showed positive signs as a potential candidate to be used as an alternative lubricant in automotive engine systems even though there is still much room for improvement.
34
BARTOLUCCI, EDOARDO. "Influence of genetic and technological factors on the quality parameters of vegetable oils". Doctoral thesis, Università Politecnica delle Marche, 2022. https://hdl.handle.net/11566/299824.
Testo completoAbstract (sommario):
Il progetto di dottorato consiste nella determinazione dei fattori genetici (cultivar), tecnologici
(tecniche di estrazione) e di raffinazione che influenzano la qualità dell’olio di oliva e di altri oli
vegetali. Nella prima parte di questo progetto saranno messi a confronto 11 oli extravergini di oliva
monovarietali, evidenziando le differenze in termini di composizione chimico-fisica, sensoriali e
verificando come la cultivar possa influenzare per il 50%, assieme ad altri fattori, la composizione
chimica e sensoriale nonché il contenuto di sostanze bioattive.
La seconda parte consiste nella determinazione dei principali costituenti dell'olio extravergine di oliva
tradizionale, denocciolati e denocciolati con la successiva aggiunta di nocciole. In particolare, acidità,
perossidi, tempo di induzione attraverso Rancimat, tocoferoli e composti organici volatili sono stati
analizzati in tre campioni di olio sopra descritti al momento dell'imbottigliamento e dopo 3, 6 e 12
mesi, verificando l'evoluzione dei parametri sopra indicati per ottimizzare il processo produttivo e
per verificare la qualità dell'olio.
Nella terza parte del progetto, i parametri di acidità, perossidi, tempo di induzione attraverso
Rancimat, tocoferoli e tocotrienoli sono stati analizzati in diversi oli vegetali (girasole, girasole alto
oleico, mais, semi d'uva, soia) e in diverse fasi di raffinazione (olio greggio, essiccato, raffinato,
sbiancato, deodorato, neutralizzato). In questo modo sono stati esaminati l'effetto della fase di
raffinazione sui vari oli e la qualità. I risultati ottenuti potranno servire a migliorare i processi
produttivi degli oli di oliva e vegetali, sia in termini di qualità che di shelf-life del prodotto.The PhD project consists of the determination of genetic (cultivars), technological (extraction techniques) and refining factors that influence the quality of olive oil and other vegetable oils. In the first part of this project, 11 monovarietal extra virgin olive oils will be compared, highlighting the differences in terms of chemical-physical composition, sensory and verifying how the cultivar can influence for 50%, together with other factors, the chemical and sensory composition as well as the content of bioactive substances. The second part consists in the determination of the main constituents of traditional extra virgin olive oil, pitted and pitted with the subsequent addition of kernels. Acidity, peroxides, induction time through Rancimat, tocopherols and volatile organic compounds were analyzed in three oil samples described above at the time of bottling and after 3, 6 and 12 months, verifying the evolution of the above parameters to optimize the production process and to verify the quality of the oil. In the third part of the project, the parameters of acidity, peroxides, induction time through Rancimat, tocopherols and tocotrienols were analyzed in different vegetable oils (sunflower, high oleic sunflower, corn, grape seeds, soybeans) and in different refining phases (crude oil, dried, refined, bleached, deodorized, neutralized). In this way, the effect of the refining phase on the various oils and the quality were examined. The results obtained will be used to improve the production processes of olive and vegetable oils, both in terms of quality and shelf life of the product,
35
Galli, F. "REDUCTION OF THE CARBON FOOTPRINT OF FUELS AND PETROCHEMICALS STARTING FROM VEGETABLE OILS". Doctoral thesis, Università degli Studi di Milano, 2015. http://hdl.handle.net/2434/332036.
Testo completoAbstract (sommario):
In this work developments and innovative studies are proposed for the current biodiesel technology in order to make the whole productive process more efficient. In particular, three main aspects were deeply investigated, the oil deacidification, as a pre-step to the oil transesterification, working on the optimization of the operative parameters and developing a suitable kinetic model able to predict, in a wide range of concentrations and temperatures, the acid conversion and the eventual double phase system formation. Moreover, the extraction of carotenes from crude palm oil was investigated, focusing on finding the operative parameters that permitted its complete preservation. Experimental results showed that at the optimized condition these molecules were adsorbed on the catalyst, giving encouraging information regarding their extraction from crude oils. Secondly, the transesterification reaction was studied in a novel way, trying to overcome the mass limitation due to the low methanol solubility in oil using a suitable co-solvent and CaO as catalyst. Good results were obtained when THF was used, the biodiesel yield was comparable to the homogeneous catalyzed process. Finally, a possible improvement of biodiesel to valuable chemical was studied. In particular the synthesis of epoxidized biodiesel was firstly optimized and then performed on biodiesel and distilled biodiesel, obtaining with this latter substrate a product with an epoxide content comparable to a commercial product, giving positive suggestion for its application as bioplasticizer.
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Valverde, Sarmiento Carmen. "10-Undecenoic acid-based biodegradable hydroxy polyesters: a platform for aminoacid bioconjugates and PEG-derived amphiphilic copolymers". Doctoral thesis, Universitat Rovira i Virgili, 2018. http://hdl.handle.net/10803/664715.
Testo completoAbstract (sommario):
El gran desenvolupament que actualment estan experimentant els biopolímers es deu fonamentalment als alts preus i a la disminució de les reserves de petroli, juntament amb la preocupació que existeix avui en dia en matèria de sostenibilitat ambiental. Entre els polímers d'origen renovable, els polièsters alifàtics són dels més estudiats ja que es consideren molt adequats per aplicacions com a biomaterials a causa de la seva biocompatibilitat i biodegradabilitat.
En aquesta tesi s'han preparat polièsters renovables mitjançant química sostenible i utilitzant derivats de l'oli de ricí, com a producte de partença. Concretament, s'han fet servir reaccions amb àcid 10-undecenoïc per obtenir els monòmers, que contenen grups funcionals àcid carboxílic i epòxid o alcohol. Tots dos tipus de monòmer són capaços d'experimentar polimerització, obtenint així polímers lineals i ramificats amb grups hidroxilo funcionalitzables. S'ha demostrat que aquests polímers són degradables enzimàtica i hidrolíticament. A més a més s'han modificat aquests polièsters amb diferents biomolècules com els aminoàcids.
Finalment, utilitzant enzims com a catalitzador s'han sintetitzat copoliésters de bloc i d’empelt a partir d'aquests monòmers o polièsters i derivats del polietilenglicol. Com a resultat s’han obtingut polímers amfifílics capaços de formar micel·les en les quals és possible encapsular drogues per ser alliberades de forma controlada.El gran desarrollo que están experimentando actualmente los biopolímeros se debe fundamentalmente a los altos precios y disminución de las reservas de petróleo, junto con la preocupación que existe hoy en día en materia de sostenibilidad ambiental. Entre los polímeros de origen renovable los poliésteres alifáticos son los que se han estudiado en mayor profundidad por ser los más adecuados como biomateriales, debido a su biocompatibilidad y biodegradabilidad. En esta tesis se han preparado poliésteres renovables mediante química sostenible y el uso de derivados de aceite de ricino como materia de partida. Concretamente, se han usado reacciones a partir del ácido 10-undecenoico para obtener monómeros que contienen grupos funcionales ácido carboxílico y epóxido o alcohol. Ambos monómeros son capaces de experimentar polimerización, obteniendo así polímeros lineales y ramificados con grupos hidroxilo funcionalizables. Se ha demostrado que estos polímeros son degradables enzimática e hidrolíticamente. Además, estos poliésteres se han modificado con diferentes biomoléculas como aminoácidos. Finalmente, utilizando enzimas como catalizador se han sintetizado copoliésteres de bloque y de injerto a partir de estos monómeros o poliésteres y derivados del polientilenglicol. Como resultado, se han obtenido polímeros amfifílicos capaces de formar micelas, en las cuales es posible encapsular drogas para ser liberadas de forma controlada.
Currently biopolymers experienced a great development due to the high prices and decrease of petroleum reserves along with the concern increasing in terms of environmental sustainability. Aliphatic polyesters are among the most studied polymers from renewable resources, because they are considered very suitable for applications as biomaterials due to their biocompatibility and biodegradability. In this thesis, renewable polyesters have been prepared from derivatives of vegetable castor oil and using sustainable chemistry. Specifically, 10-undecenoic acid has been used to synthesize the monomers which contain carboxylic acid and epoxide or alcohol. These monomers by polymerization lead to linear or branched polymers with available reactive hydroxyl groups. It has been shown that these polymers are enzymatically and hydrolytically degradable. In addition, these polyesters have been modified with different biomolecules as aminoacids. Finally, using enzymes as catalyst have been synthesized block and grafted copolyesters from these monomers or polyesters and polyethylene glycol derivatives. As result, amphiphilic polymers capable of forming micelles have been synthesized, which can encapsulate drugs to be released.
37
Xiao, Haiyi. "LOW TRANS FATTY ACID CONTAINING HYDROGENATED EDIBLE OILS". Miami University / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=miami1196130854.
Testo completo
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Binti, Shaarani Farra Wahida. "Synthesis and characterization of polycarbonates from epoxidized vegetable oils, propylene oxide and carbon dioxide". Doctoral thesis, Universitat Politècnica de Catalunya, 2021. http://hdl.handle.net/10803/672164.
Testo completoAbstract (sommario):
The current research is primarily focused on the preparation of a polycarbonate using epoxidized linseed oil (ELO) and epoxidized soybean oil (ESO) as feedstocks. The presence of unsaturation in vegetable oil structure enables chemical modifications to introduce epoxy group which further used to synthesize polycarbonate via catalytic copolymerization with carbon dioxide (CO2). In this study, with the presence of heterogeneous catalyst a mixture of epoxidized vegetable oil and propylene oxide (PO) were reacted with CO2. Synthesis of polycarbonate via this pathway helps to lessen the reliance on petroleum-based feedstocks and besides employing renewable raw materials meets the 7th principle of 12 Principles of Green Chemistry that contributes to sustainability in chemistry.
The research work is divided into four phases. The first phase comprises preliminary studies whereby preparation of a heterogeneous catalyst for the copolymerization of epoxide with CO2 were made. Catalyst screening tests showed that cobalt- zinc double metal cyanide (Co-Zn DMC), a heterogenous catalyst commonly employed in the copolymerization reaction was feasible for cyclohexene oxide (CHO)/CO2 and PO/CO2 copolymerization. Then in-situ epoxidation of unsaturated fatty acids using selected vegetable oils were carried out to modify vegetable oil to epoxidized vegetable oil. The molar ratio of 0.4:0.1:1.7 (organic acid: double bonds: hydrogen peroxide) were applied and the epoxidation reaction took place at 70ºC for five hours. No formation of polymer was observed from the terpolymerization of epoxidized olive oil (EOO), epoxidized palm oil (EPO) and epoxidized sunflower oil (ESFO) most likely due to the low content of epoxy group of the epoxide oils used. However, from the preliminary studies a promising result were obtained from both ELO and ESO whereby a polymer has been successfully developed from the copolymerization reaction.
The second phase of the work is focused on the copolymerization of ESO, PO and CO2 catalyzed by Co-Zn DMC. Products comprises of mixture of poly(propylene carbonate), cyclic carbonate and polyether unit. The Mn of the polymeric products recorded is 6498 g. mol-1 with the percentage incorporation of ESO in the polymer is only 7.8%.
The third phase of the work is dedicated on the development of a poly(carbonate-co-ether) using ELO as the starting material. The terpolymerization reaction were conducted at fixed CO2 pressure of 5 MPa and various catalyst loading, reaction temperature and reaction time. At CO2 pressure of 5 MPa, reaction temperature of 60ºC, reaction time of 24 h and catalyst loading of 0.2 g, the resultant polymer with maximum Mn of 6.21 x 105 g.mol-1 and PDI of 1.05 was recorded.
Finally, the ability of the synthesized polymer to degrade was study under aerobic condition. The aerobic biodegradation of the test materials was determined under controlled composting conditions by analysis of evolved CO2 using an in-house built direct measurement respirometric (DMR) system. Results from this study discloses that 44.6% of PC-ELO and 51.8% of PC-ESO were degraded at the end of trial period. Both polymers were able to degrade most likely due to the co-monomer employed in the copolymerization reaction are renewable and bio based.La recerca que es descriu es centra principalment en la preparació de policarbonats utilitzant oli de llinosa epoxidat (ELO) i oli de soja epoxidat (ESO) com a matèries primeres. La presència de insaturació en l'estructura de l'oli vegetal permet modificacions químiques per a introduir un grup epoxi que després es fa servir per sintetitzar els policarbonats mitjançant copolimerització catalítica amb diòxid de carboni (CO2). En aquest estudi, amb la presència d'un catalitzador heterogeni, es va fer reaccionar una barreja d'oli vegetal epoxidat i òxid de propilè (PO) amb CO2. La síntesi de policarbonat a través d'aquesta via ajuda a disminuir la dependència de matèries primeres a força de petroli i, a més d'emprar matèries primeres renovables, compleix amb el setè principi dels 12 principis de la química verda que contribueix a la sostenibilitat en la química. El treball de recerca es divideix en quatre fases. La primera fase comprèn estudis preliminars mitjançant els quals es va realitzar la preparació d'un catalitzador heterogeni per a la copolimerització de l'epòxid amb CO2. Les proves de selecció de catalitzadors van mostrar que el cianur doble metàl·lic de cobalt-zinc (Co-Zn DMC), un catalitzador heterogeni comunament emprat en la reacció de copolimerització, era factible per a la copolimerització d'òxid de ciclohexè (CHO)/CO2 i PO/CO2. Després es va dur a terme l'epoxidació in situ d'àcids grassos insaturats utilitzant olis vegetals seleccionats per modificar el triglicèrid en oli vegetal epoxidat. Es va aplicar la relació molar d'0,4: 0,1: 1,7 (àcid orgànic: dobles enllaços: peròxid d'hidrogen) i la reacció d'epoxidació va tenir lloc a 70 °C durant cinc hores. No es va observar formació de polímer a partir de la terpolimerización d'oli d'oliva epoxidat (EOO), oli de palma epoxidat (EPO) i oli de gira-sol epoxidat (ESFO) molt probablement a causa de el baix contingut de grups epoxi. No obstant això, dels estudis preliminars es va obtenir un resultat prometedor tant d'ELO com d'ESO mitjançant el qual s'ha desenvolupat amb èxit un polímer a partir de la reacció de copolimerització. La segona fase de la feina se centra en la copolimerització d'ESO, PO i CO2 catalitzada per Co-Zn DMC. Els productes es componen d'una barreja de poli (carbonat de propilè), carbonat cíclic i unitat de polièter. El Mn dels productes polimèrics registrats és 6498 g·mol-1 amb el percentatge d'incorporació d'ESO en el polímer és només de l'7,8%. La tercera fase de la feina està dedicada a el desenvolupament d'un poli (carbonat-co-èter) utilitzant ELO com a material de partida. La reacció de terpolimerización es va dur a terme a una pressió fixa de CO2 de 5 MPa i diverses càrregues de catalitzador, temperatura de reacció i temps de reacció. A una pressió de CO2 de 5 MPa, una temperatura de reacció de 60 °C, un temps de reacció de 24 hi una càrrega de catalitzador de 0,2 g, es va registrar el polímer resultant amb un Mn màxim de 6,21 x 105 g·mol-1. Finalment, es va estudiar la capacitat de degradació aeròbica del polímer sintetitzat. La biodegradació aeròbica dels materials de prova es va determinar en condicions controlades de compostatge mitjançant l'anàlisi de el CO2 desprès utilitzant un sistema respiromètric de mesurament directe (DMR) de construcció pròpia. Els resultats d'aquest estudi revelen que el 44,6% de PC-ELO i el 51,8% de PC-ESO es van degradar a la fi de el període de prova. Tots dos polímers van poder degradar molt probablement pel fet que el comonòmer emprat en la reacció de copolimerització és renovable i de base biològica.
La investigación que se describe se centra principalmente en la preparación de policarbonatos utilizando aceite de linaza epoxidado (ELO) y aceite de soja epoxidado (ESO) como materias primas. La presencia de insaturación en la estructura del aceite vegetal permite modificaciones químicas para introducir un grupo epoxi que luego se usa para sintetizar los policarbonatos mediante copolimerización catalítica con dióxido de carbono (CO2). En este estudio, con la presencia de un catalizador heterogéneo se hizo reaccionar una mezcla de aceite vegetal epoxidado y óxido de propileno (PO) con CO2. Los productos poliméricos producidos se caracterizaron utilizando espectroscopía de infrarrojos por transformada de Fourier (FTIR), espectroscopía de resonancia magnética nuclear de protones (1H NMR) y cromatografía de permeación en gel (GPC). La síntesis de policarbonato a través de esta vía ayuda a disminuir la dependencia de materias primas a base de petróleo y, además de emplear materias primas renovables, cumple con el séptimo principio de los 12 principios de la química verde que contribuye a la sostenibilidad en la química. El trabajo de investigación se divide en cuatro fases. La primera fase comprende estudios preliminares mediante los cuales se realizó la preparación de un catalizador heterogéneo para la copolimerización del epóxido con CO2. Las pruebas de selección de catalizadores mostraron que el cianuro doble metálico de cobalto-zinc (Co-Zn DMC), un catalizador heterogéneo comúnmente empleado en la reacción de copolimerización, era factible para la copolimerización de óxido de ciclohexeno (CHO) / CO2 y PO / CO2. Luego se llevó a cabo la epoxidación in situ de ácidos grasos insaturados utilizando aceites vegetales seleccionados para modificar el triglicérido en aceite vegetal epoxidado. Se aplicó la relación molar de 0,4: 0,1: 1,7 (ácido orgánico: dobles enlaces: peróxido de hidrógeno) y la reacción de epoxidación tuvo lugar a 70ºC durante cinco horas. No se observó formación de polímero a partir de la terpolimerización de aceite de oliva epoxidado (EOO), aceite de palma epoxidado (EPaO) y aceite de girasol epoxidado (ESFO) muy probablemente debido al bajo contenido de grupos epoxi. Sin embargo, de los estudios preliminares se obtuvo un resultado prometedor tanto de ELO como de ESO mediante el cual se ha desarrollado con éxito un polímero a partir de la reacción de copolimerización. La segunda fase del trabajo se centra en la copolimerización de ESO, PO y CO2 catalizada por Co-Zn DMC. Los productos se componen de una mezcla de poli (carbonato de propileno), carbonato cíclico y unidad de poliéter. El Mn de los productos poliméricos registrados es 6498 g.mol-1 con el porcentaje de incorporación de ESO en el polímero es solo del 7,8%. La tercera fase del trabajo está dedicada al desarrollo de un poli (carbonato-co-éter) utilizando ELO como material de partida. La reacción de terpolimerización se llevó a cabo a una presión fija de CO2 de 5 MPa y varias cargas de catalizador, temperatura de reacción y tiempo de reacción. A una presión de CO2 de 5 MPa, una temperatura de reacción de 60ºC, un tiempo de reacción de 24 hy una carga de catalizador de 0,2 g, se registró el polímero resultante con un Mn máximo de 6,21 x 105 g.mol-1. Finalmente, se estudió la capacidad de degradación del polímero sintetizado en condiciones aeróbicas. La biodegradación aeróbica de los materiales de prueba se determinó en condiciones controladas de compostaje mediante el análisis del CO2 desprendido utilizando un sistema respirométrico de medición directa (DMR) de construcción propia. Los resultados de este estudio revelan que el 44,6% de PC-ELO y el 51,8% de PC-ESO se degradaron al final del período de prueba. Ambos polímeros pudieron degradarse muy probablemente debido a que el comonómero empleado en la reacción de copolimerización es renovable y de base biológica.
39
Alattar, Hasan. "Effect of heat treatment on α-Tocopherol content and antioxidant activity of vegetable oils". Thesis, McGill University, 2013. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=119680.
Testo completoAbstract (sommario):
The objective of this research was to investigate the effect of heating on α-Tocopherol content and antioxidant activity of different vegetable oils (EVOO, canola and palm oil). The highest α-Tocopherol content was found in EVOO followed by canola oil and palm oil (323 ±5, 271 ±2 and 174 ±2 µg/ml) respectively. The effect of heat was done at 70, 100 and 130 oC, for time intervals of 0.5, 1, 1.5 and 2 h. Thermal degradation of α-Tocopherol in the oils was minimal at 70 oC and increased at 100 oC and 130 oC. Heating at 130 oC for 2 h resulted in 100, 24 and 44 % degradation of α-Tocopherol in EVOO, canola oil and palm oil respectively; EVOO was completely degraded after 1.5 h heating at 130 oC. Use of 2 cooking methods, pan-frying (250 oC, 5 min) and oven cooking (130 oC, 30 min) resulted in the degradation of α-Tocopherol in the oils. In the pan-frying method, both EVOO and palm oil were completely degraded and canola oil showed 42 % degradation. With the oven cooking method the degradation for EVOO, canola oil and palm oil were 18, 13 and 10 %, respectively. The antioxidant activity was highest with canola oil followed by palm oil and EVOO (59 ±1.72, 51 ±0.84 and 46 ±0.91 %), respectively. At 70 oC there was no significant decrease in the antioxidant activity of the heated oils. At 100 oC, EVOO showed highest reduction in antioxidant activity followed by canola oil and palm oil. At 130 oC, the antioxidant activity decreased gradually in the oil samples. The highest decrease was observed with EVOO followed by canola oil and palm oil. The decrease of antioxidant activity in oil samples was also observed with both pan-frying and oven cooking methods, with greater reduction in antioxidant activity using the pan-frying method.L'objectif de cette recherche a été d'étudier l'effet de la chaleur sur la quantité d'α-tocophérol et sur l'activité antioxydant de différentes huiles végétales (l'huile d'olive extra vierge, l'huile de canola, et l'huile de palme). La quantité la plus élevée d'α-Tocophérol a été trouvée dans l'huile d'olive extra vierge, suivie par l'huile de canola et l'huile de palme (323 ±5, 271 ±2 and 174 ±2 µg/ml) respectivement. L'effet de la chaleur a été étudié à 70, à 100 et à 130 oC durant 0.5, 1, 1.5 et 2 h. La dégradation thermale d'α-Tocophérol dans les huiles a été minimale à 70 °C et a augmenté à 100 et 130 °C. Chauffer à 130 oC durant 2 h a mené à la dégradations de 100, 24 et 44 % d'α-Tocophérol dans l'huile d'olive extra vierge, dans l'huile de canola, et dans l'huile de palme, respectivement; l'huile d'olive extra vierge a été complètement dégradée après 1.5 h de chauffage à 130 oC. L'utilisation de deux différents façons de cuire, l'utilisation de la poêle (250 oC, 5 min) et l'utilisation du four (130 oC, 30 min), a mené à la dégradation d'α-Tocophérol dans les huiles. En utilisant la poêle, l'huile d'olive extra vierge et l'huile de palme ont été complètement dégradées et l'huile de canola a démontré une dégradation de 42 %. En utilisant le four, la dégradation de l'huile d'olive extra vierge, de l'huile de canola, et de l'huile de palme a été de 18, 13 et 10 % respectivement. L'activité antioxydant des échantillons a été le plus élevé avec l'huile de canola, suivi par l'huile de palme et par l'huile d'olive extra vierge (59 ±1.72, 51 ±0.84 et 46 ±0.91 %), respectivement. À 70 oC, il n'y avait pas de réduction significative dans l'activité antioxydant des huiles chauffées. À 100 oC, l'huile d'olive extra vierge a démontré une réduction maximale en activité antioxydant suivi par l'huile de canola et par l'huile de palme. À 130 oC, l'activité antioxydant des huiles a baissé graduellement. La réduction la plus élevée a été observée avec de l'huile d'olive extra vierge, suivie par l'huile de canola et par l'huile de palme. La réduction en activité antioxydant dans les échantillons d'huile a été aussi observée avec les deux façons de cuire, d'où une réduction plus importante en activité antioxydant a été observée en utilisant la poêle.
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Marais, Christiaan De Wet. "The determination of cis and trans fatty acid isomers in partially hodrogenated plant oils /". Link to online version, 2007. http://hdl.handle.net/10019/399.
Testo completo
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Dos, Santos Pereira Maria da Gloria. "Bacterial degradation of linseed and sunflower oils in salt marsh sediments". Thesis, Bangor University, 1999. https://research.bangor.ac.uk/portal/en/theses/bacterial-degradation-of-linseed-and-sunflower-oils-in-salt-marsh-sediments(4697b1cb-815d-46a6-8b52-880c0cfcf62c).html.
Testo completoAbstract (sommario):
This work investigated the consequences of vegetable oils spills in salt marsh sediments. The role of autochthonous bacteria in the oils degradation and degradative pathways were also studied 'in situ' and 'in vitro'. Simulated spills of sunflower and linseed oils revealed that both oils penetrated the sediments at a rate of 10-7 CM2 s-1. However, whereas 60% of the linseed oil had disappeared from the sediments after 2 months most of the sunflower oil remained after 6 months. Differences were noted in the adsorption of the oils to sediment particles and the depth at which they accumulate and these factors most likely influenced the route of the oil degradation and the sediments properties such as permeability. The contamination of the sediments with vegetable oils lead to a noticeable reduction in the abundance of plant roots and infauna. The abundance of aerobic, anaerobic and sulphate reducing bacteria in the sediments was increased by the addition of both oils, with linseed oil supporting greater bacterial density than sunflower oil. During the course of the experiment the relative abundance of oil degrading bacteria also increased. As a consequence of the increased bacterial activity, the sediments pH and Eh decreased and anoxic conditions were established, earlier in the case of linseed than that of sunflower oils. The degradation of the oils appeared to be a sequential process, initiated by the aerobic and/or anaerobic bacteria and continued by the sulphate reducing bacteria which themselves where unable to utilise the raw oils. The original composition of both oils underwent alterations mostly associated with their main fatty acid: the concentration of 18: 3(o3 and 18: 2o)6 in linseed and sunflower oil, respectively, decreased whereas that of the remaining fatty acids increased. As a result of the bacterial degradation of the vegetable oils 'new' fatty acids were detected and their identification was attempted using GC-MS analysis of their picolinyl and methyl esters. Various degradative pathways of linseed and sunflower oils involving the formation of the 'new' fatty acids are suggested with isomerisation, hydrogenation and P-oxidation as the primary routes for the degradation.
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Pan, Xiao. "Novel Biobased Resins using Sucrose Esters of Plant Oils". Diss., North Dakota State University, 2011. https://hdl.handle.net/10365/29636.
Testo completoAbstract (sommario):
Interest in using renewable raw materials to prepare biobased monomers, polymers, and materials is rapidly increasing. The goal of the research described is to develop branched polyesters of plant oil fatty acids, using different core pol yo ls (i.e. sucrose, dipentaerythritol, and tripentaerythritol) and plant oils (i.e. linseed, safflower, and soybean), into curing systems that have potential uses in applications such as coatings, composites, and adhesives. This study is mainly focused on the use of sucrose as the core
polyol in the soyate resins. Sucrose esters and their derivatives have a compact structure, high density, and high functionality-double bonds, epoxides, or hydroxyls. When considering the use of sucrose
ester compounds to form cross linked materials, the rigid core of sucrose can potentially impart hardness to the thermoset, and the high functionality can lead to rapid gelation and high cross link density. Thus, these novel biobased resins using sucrose esters of plant oils have the potential to be a significant advance in biobased resin technology, as well as to be competitive with the conventional petroleum-based resins.
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Guo, Yan. "Alkaline-catalyzed production of biodiesel fuel from virgin canola oil and recycled waste oils". Click to view the E-thesis via HKUTO, 2005. http://sunzi.lib.hku.hk/hkuto/record/B36584927.
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Normand, Laura. "The effect of minor components on the frying stability of regular and modified vegetable oils". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ32202.pdf.
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45
Kupranycz, Donna B. (Donna Bohdanka). "Effects of thermal oxidation on the constitution of butterfat, butterfat fractions and certain vegetable oils". Thesis, McGill University, 1986. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=72822.
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Maisonneuve, Lise. "Vegetable oils as a platform for the design of sustainable and non-isocyanate thermoplastic polyurethanes". Thesis, Bordeaux 1, 2013. http://www.theses.fr/2013BOR15218/document.
Testo completoAbstract (sommario):
Cette thèse porte sur la synthèse de polyuréthanes thermoplastiques plus durables à partir de dérivés des huiles végétales. La première voie étudiée est basée sur la réaction, largement utilisée, entre un diol et un diisocyanate. Aussi, pour s’affranchir de l’utilisation des diisocyanates toxiques, une approche via la polyaddition entre un bis carbonate cyclique et une diamine a également été étudiée. Pour ce faire des précurseurs bi-fonctionnels : diols, bis carbonates cycliques à 5 et 6 chainons et diamines ont été préparés à partir de dérivés de l’huile de tournesol (oléate de méthyle) et de l’huile de ricin (undécénoate de méthyle et acide sébacique). Les propriétés thermo-mécaniques des polyuréthanes et poly(hydroxyuréthane)s thermoplastiques obtenus ont pu être ajustées par le choix adapté de la structure chimique des précurseurs (gras) utilisés. Les travaux réalisés démontrent un effet de la taille du cycle du carbonate sur la réactivité. En effet, les (bis) carbonates cycliques à 6 chainons se sont avérés plus réactifs que leurs homologues à 5 chainons. De plus, la synthèse de diamines via un intermédiaire dinitrile semble très prometteuse pour le « design » d’une plateforme de diamines issues d’acides gras et de poly(hydroxyuréthane)s entièrement bio-sourcésThis thesis aims to synthesize more sustainable thermoplastic polyurethanes from vegetable oil derivatives. The first route that has been investigated is based on the well-known reaction between a diol and a diisocyanate. Then to avoid the use of diisocyanates, the route via the polyaddition of a bis cyclic carbonate and a diamine have been studied as well. For this purpose, bifunctional precursors such as diols, bis 5- and 6-membered cyclic carbonates and diamines have been prepared from sunflower oil derivative (methyl oleate) and castor oil derivatives (methyl undecenoate and sebacic acid) The thermo-mechanical properties of the PUs have been modulated by designing and selecting the chemical structure of the (fatty acid-based) monomers. The performed model reaction kinetics revealed the higher reactivity of the 6-membered cyclic carbonates compare to the 5-membered ones. Finally, the developed route to fatty acid-based diamines via dinitriles synthesis in mild conditions was really efficient and this route is really promising to develop a fatty acid based-diamines platform and fully bio-based poly(hydroxyurethane)s
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Peacock, Lesley. "Isomeric fatty acids and platelet function". Thesis, University of Aberdeen, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.253708.
Testo completoAbstract (sommario):
1. Cis unsaturated fatty acids were shown to inhibit porcine platelet aggregation in response to both collagen and thrombin. Fatty acids with a trans double bond had an anti-aggregatory effect on collagen-induced aggregation but this was significantly less than that observed with the cis equivalent and was diminished as the dose of agonist increased. Thrombin-induced platelet aggregation was unchanged or slightly potentiated by trans isomers. 2. Both the cis and trans isomeric acids inhibited collagen-induced TXB2 production. The trans unsaturated fatty acids also inhibited TXB2 production in response to thrombin, even though they did not inhibit thrombin induced platelet aggregation. 3. Unlike arachidonic acid, the cis and trans mono-unsaturated fatty acids were not rapidly incorporated into membrane phospholipids but modified platelet aggregation whilst in the free acid form. 4. Pre-incubation of platelets with either cis or trans delta 13, 18:1, selectivity inhibited the incorporation of radio-labelled arachidonic acid into membrane PS. 5. Cis and trans unsaturated delta 13, 18:1, inhibited the initial turnover of membrane PI in response to thrombin possibly by an inhibitory effect on PI-specific phospholipase C. After 5 minutes, however, the level of arachidonic acid released from both PI and PE was increased in the presence of the isomeric fatty acids. This may have been via a potentiation of the action of phospholipase A2. 6. An increased release of arachidonic acid could result in the inhibition of aggregation if metabolised via the 12-lipoxygenase pathway, as the end products of this sytem have direct anti-aggregatory activity and inhibit the cyclo-oxygenase enzymes thus reducing TXA2 synthesis. 7. Cis unsaturated fatty acids, which produce a greater level of membrane disruption than the trans, may lead to more efficient channelling of the released arachidonic acid in the direction of the lipoxygenase pathway, and thereby produce a greater inhibition of aggregation. The possibility remains that the cis isomers have another, as yet unidentified mechanism by which they inhibit platelet aggregation.
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Heaton, Thomas. "Characterisation of waste vegetable oils used as binders for masonry units made entirely of waste materials". Thesis, University of Leeds, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.551270.
Testo completoAbstract (sommario):
Vegeblocks are masonry units made from 100% waste materials. They use waste vegetable oil as a binder, and the manufacture process involves heat curing of a block made from a mixture of the binder and waste aggregates. Research into long-term properties and enhancement of the manufacture process of these units requires an understanding of the chemistry that occurs during this process. Analysis of the binder by a mixture of spectroscopy and chromatography indicates that the reactions are characterised by consumption of unsaturated hydrocarbons in the seed oils to form products of hydrolysis, cross-linking and oxidation, supported by the literature concerned with thermal stress and oxidation of vegetable oils. Though strength gain can be directly linked to the consumption of double bonds, other physical properties are more dependent upon the aggregate mixture and manufacture process. This work demonstrates the potential and limitations of several sophisticated techniques used to analyse the material and provides a basis upon which a holistic understanding of the matrix can be built.
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Ruiz, Villán Lorena. "Valorización del aceite de ricino en química de polímeros: Síntesis de poliésteres y poliuretanos a partir de heptanal". Doctoral thesis, Universitat Rovira i Virgili, 2017. http://hdl.handle.net/10803/461094.
Testo completoAbstract (sommario):
En la actualitat, els poliuretans i els polièsters són dos dels materials polimèrics més importants ia que se poden utilitzar en multitud de camps donada la seva versatilitat. Els últims avenços en la investigació sobre aquest tipus de polímers venen donats per la creixent demanda de processos més sostenibles i l'ús de matèries primeras d'origen renovable. Algunes d'aquestes són els olis vegetals, com l'oli de ricí el qual no és apte per el consum humà. A partir d'aquest oli, s'obté l'àcid ricinoleic amb un rendiment elevat. Aquest àcid es converteix mitjançant piròlisi en àcid undecenoic i heptanal. L'àcid undecenoic ha estat àmpliament utilitzat per a la síntesi de diferents monòmers i polímers amb elevats rendiments i sostenibilitat química. En canvi el heptanal, apreciat per les qualitats olfactives d'alguns dels seus derivats, és àmpliament utilitzat com un intermediari de síntesi per a la indústria de fragàncies i aromes. Malgrat l'ús d'aquest compost com a producte intermedi químic en la química de polímers és pràcticament inexistent.
En la present tesi s'ha investigat una àmplia varietat de transformacions químiques per obtenir monòmers bifuncionals i renovables així com els seus polièsters i poliuretans, utilitzant heptanal com a matèria primera. Tanmateix, s'han desenvolupat diferents nanosistemes basats en aquests polímers com són micel·les o nanocàpsules. Com a conclusió general, s'ha demostrat que la transformació de l'heptanal en monòmers i polimers mitjançant processos mediambientalment compatibles és una alternativa sostenible en química de polimers.En la actualidad, los poliuretanos y los poliésteres son dos de los materiales poliméricos más importantes ya a que se pueden utilizar en multitud de areas debido a su versatilidad. Los últimos avances en la investigación sobre este tipo de polímeros son impulsados por la creciente demanda de procesos más sostenibles y el uso de materias primas renovables. Algunas de estas materias primas renovables son los aceites vegetales, como el aceite de ricino el cual no es comestible. A partir de este aceite, se obtiene el ácido ricinoleico con un alto rendimiento. Este ácido se convierte mediante pirólisis en ácido undecenoico y heptanal. El ácido undecienoico ha sido ampliamente utilizado para la síntesis de diferentes monómeros y polímeros con elevados rendimientos y sostenibilidad química. En cambio el heptanal, apreciado por las cualidades olfativas de algunos de sus derivados, es ampliamente utilizado como un intermediario de síntesis para la industria de fragancias y aromas. Sin embargo, el uso de este compuesto como producto intermedio químico en la química de polímeros es prácticamente inexistente. En esta tesis se ha investigado una amplia variedad de transformaciones químicas para obtener monómeros bifuncionales y renovables así como sus poliésteres y poliuretanos, utilizando heptanal como materia prima. Además, se desarrollaron diferentes nanosistemas basados en estos polímeros como son micelas o nanocápsulas. Como conclusión general, se ha demostrado que la transformación de heptanal en monómeros y polimeros mediante procesos mediambientalmente compatibles es una alternativa sostenible en química de polimeros.
Nowadays, polyurethanes and polyesters are two of the most important polymeric materials that can be used in different applications due to their versatility. The recents advances in the research of these kinds of polymers are driven by the growing demand for greener processes and the use of renewable raw materials. Some of these renewable raw materials are vegetable oils, such as non-edible castor oil. From this oil, ricinoleic acid is obtained in a high yield. Ricinoleic acid is converted by chemical thermal cracking process into undecenoic acid and heptanal. Undecenoic acid has been widely used for the synthesis of different monomers and polymers combining high performance and sustainability. Heptanal, appreciated for the olfactory qualities of certain of its derivatives, is widely used as a synthesis intermediate for fragrance and aroma industry. However, the use of C7 cut of castor oil thermal cracking as a chemical intermediate in polymer chemistry is practically non-existent. In this thesis, we have explored a wide variety of chemical transformations to obtain bifunctional biobased monomers and their polyesters and polyurethanes, using heptanal such as raw material. Furthermore, the development a novel nanoparticles with some of these materials was carried out. As a general conclusion, the transformation of heptanal into monomers and polymers using environmentally friendly procedures has been shown to be a sustainable alternative in polymer chemistry.
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ANDRADE, ANDREIA B. N. de. "Desenvolvimento de um sistema de liberação controlada de princípios ativos do oleo de Azadirachta indica A. Juss em matriz de poli(álcool vinílico) (PVA) para aplicações em veterinária". reponame:Repositório Institucional do IPEN, 2013. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10522.
Testo completoAbstract (sommario):
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Dissertação (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP