Dissertations / Theses on the topic 'Furanic polymers'
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Dellière, Pierre. "Résines furaniques modulables et durables." Electronic Thesis or Diss., Université Côte d'Azur, 2023. http://www.theses.fr/2023COAZ4106.
Full textThis doctoral project was conducted within the ANR FUTURES (FUranic TUnable REsins for Sustainable materials) project.Poly(furfuryl alcohol) is a bio-based thermoset with excellent chemical and thermal properties. Yet, it may mechanically behave in a brittle manner. The aim of the project was to pave the way for new applications of poly(furfuryl alcohol) by exploiting side reactions occurring during polymerization. This leads to additional functionalities that could be exploited to, among others, reduce the brittleness of the material.First, the reactive carbonyl resulting from the furan ring opening side reaction were quantified by potentiometry and quantitative NMR. The key factors that were influencing the carbonyl content were assessed and water proved to be the main one. The chemical nature of the carbonyls was thoroughly investigated by 2D NMR and a new surface crosslinking phenomenon was identified and explained. The impact of this surface crosslinking on the materials' properties was evaluated. Finally, the presence of carbonyls due to the ring-opening side reaction was exploited to functionalize the polymer. The use of large flexible amines allowed to shift the materials properties from brittle to ductile therefore paving to way to new applications for poly(furfuryl alcohol). Finally, factors governing the properties of the amine-functionalized materials were studied
Coutterez, Claire. "Synthèse, caractérisation et étude des propriétés d'oligomères et polymères hétéroarylène vinylènes." Grenoble INPG, 1998. http://www.theses.fr/1998INPG0163.
Full textCousin, Thibault. "Synthesis and molecular modelling of bio-based polyamides." Phd thesis, INSA de Lyon, 2013. http://tel.archives-ouvertes.fr/tel-00952848.
Full textGunes, Arzu. "Synthesis Of A Novel Series Of Furan And Fluorene Containing Monomers And Their Polymers." Master's thesis, METU, 2011. http://etd.lib.metu.edu.tr/upload/12613768/index.pdf.
Full text2,7-di(furan-2-yl)-9H-fluoren-9-one (FOF), 2-(2-(furan-2-yl)-9H-fluoren-7-yl)furan (FFF), and 2-(2-(furan-2-yl)-9,9-dihexyl-9H-fluoren-7-yl)furan (FHF) were synthesized and their electrochemical polymerization were achieved via potential cycling. Optical and electrochemical properties of the polymers, poly(2,7-di(furan-2-yl)-9H-fluoren-9-one) (PFOF), poly(2-(2-(furan-2-yl)-9H-fluoren-7-yl)furan (PFFF) and poly(2-(2-(furan-2-yl)-9,9-dihexyl-9H-fluoren-7-yl)furan) (PFHF) were investigated and it was found that polymer films exhibit reversible redox behavior (Epox = 1.083 V for PFOF, Epox= 0.915 V for PFFF and Epox= 0.985 V for PFHF) accompanied with a reversible electrochromic behavior, orange to green for PFOF, yellow to dark blue for PFFF and orange to green for PFHF during oxidation. Their band gap values (Eg) were found to be 2.32, 2.49 and 2.61 eV for PFOF, PFFF and PFHF, respectively.
Ghorbel, Inès. "Elaboration, caractérisation et mise en œuvre de matériaux polymères à base de polysemicarbazides et polyester furanique bio-sourcés." Thesis, Lyon, INSA, 2013. http://www.theses.fr/2013ISAL0013.
Full textThis work aims at elaborating, characterising and processing polymer materials based on bio-sourced polysemicarbazides and furanic polyesters. The study has three main parts : Synthesis and optimisation of the synthesis of poly(acylsemicarbazide)s, elaboration of polymer blends based on furanic polymers (PEF or PSC) with PET, PLA and PHA and elaboration of new furano-aliphatic copolyesters by ring opening polymerisation (PEF/PCL) or by inter-exchange reactions between ’homopolymers (PEF/PCL, PEF/PLA et PEF/PHA) in the melt. The first chapter reports on the synthesis of a serie of bifuranic dihydrazides and on the study of their reactivity with several aromatic diisocyanates in order to elaborate furano-aromatic polyacylsemicarbazides. The behaviour of model monomer systems in various experimental conditions is studied in order to d’optimise the polycondensation processbefore transfering it to several monomer combinations. In the second chapter, we study the elaboration of new materials based on furanic polymers (PEF or PSC) blended with polyesters in the melt. 3 kinds of blends based on furanic polyesters / aliphatic and aromatic polyesters. The third chapter is devoted to the synthesis of furanic polyesters with controlled ends : dihydroxy-PEF (PEF di-OH), dicarboxylate-PEF (PEF di-COOH), diethylester-PEF (PEF di-COOEt) as well as PEF with mixed ends (PEF di-OH/COOEt). The latest have been used for the elaboration of new furano-aliphatic polyesters by ring opening polymerisation (PEF /PCL) or after interexchange reaction in melt homoplymer blends (PEF/PLA, PEF/PHA and PEF/PCL)
Baret, Fanton Véronique. "Contribution à l'étude des polymères furaniques photoactifs." Grenoble INPG, 1995. http://www.theses.fr/1995INPG0110.
Full textNasr, Kifah. "Enzyme-catalyzed synthesis of polyesters by step-growth polymerization : a promising approach towards a greener synthetic pathway." Electronic Thesis or Diss., Université de Lille (2018-2021), 2021. http://www.theses.fr/2021LILUR030.
Full textEnzyme-catalyzed polymerization have been witnessing a growing attention in recent years as an eco-friendly substitute to metal-based catalysis. The objective of our work is to synthesize a series of polyesters via enzymatic catalysis based on different aliphatic and aromatic diols and diesters, where we focused on the influence of reaction parameters, monomer structures, and depicted the advantages and limitation of enzymatic catalysis in polymer synthesis. The enzyme used throughout our work was Novozym 435, a lipase from Candida antarctica, immobilized on an acrylic resin. In Chapter 1, we reviewed the different methods and approaches used in the literature to synthesize polymers via enzymatic catalysis. In Chapter 2, we performed the reaction between hexane-1,6-diol and diethyl adipate via a two-step polycondensation approach where we monitored the effect of certain parameters on the number average molecular weight (Mn). The influence of temperature, vacuum, and the amount of enzyme loading were determined using a central composite design. Other factors such as the reaction media, oligomerization time, and catalyst recyclability were also assessed. In Chapter 3 furan-based copolyesters were synthesized, where we showed that we can incorporate higher amounts of furan when using aliphatic diols with longer chains such as dodecane-1,12-diol. In Chapter 4, levoglucosan, an anhydrous 6-carbon ring structure and a pyrolysis product of carbohydrates such as starch and cellulose, was reacted against different chain length diesters in the presence of aliphatic diols and Novozym 435 as a catalyst. The polyesters produced were limited in their number average molecular weight (Mn) and the amount of levoglucosan that was successfully incorporated into the polymeric structure. Nevertheless, by increasing the chain length of the diester, we were able to produce a copolymer containing higher amounts of levoglucosan and a higher molecular weight
Dillingham, Keith Alfred. "The preparation and modification of polyvinylfuran, copolymers of vinylfuran and styrene, and polyacenaphthylene." Thesis, Lancaster University, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.282364.
Full textMarotta, Angela. "Résines thermodurcissables et nanocomposites époxydes renouvelables à base de furanne pour les applications de revêtement." Thesis, Université Côte d'Azur (ComUE), 2019. http://www.theses.fr/2019AZUR4003/document.
Full textResearch on bio-based polymers is rapidly increasing in last years, pushed by growing environmental and economic concerns, as well as by the uncertainty about future availability of finite petrochemical resources. Sustainability is a keyword in this process. In this frame, products that are respectful towards the environment, including eco-compatible building blocks and additives, are now researched to replace petroleum-based polymers with those derived from naturally occurring feedstocks. Epoxy resins are very versatile thermosetting polymers, extremely resistant to corrosion, moisture and chemicals, with good adhesive strength toward most materials (wettability) and low shrinkage upon curing. Due to their high glass transition temperatures and excellent mechanical strength, epoxy resins are widely employed in a broad range of applications, such as electronics, structural adhesives, aerospace composites and protective coatings. More than two-thirds of epoxy resins nowadays are based on diglycidyl ether of bisphenol A. In this industry the trend to replace petrol-derived materials with bio-based ones is related also to the necessity to substitute the Bisphenol A (BPA), a controversial building block recognized as an endocrine disrupter and reprotoxic substance. In particular in application as coating, the use of BPA results in hazard for customers of food and beverage products packed into containers treated with epoxy resins. The effects of human body contamination caused by BPA are diabetes, cardiovascular diseases, altered liver enzymes and reproductive apparatus damages. For these reasons, this molecule has been banned in many countries for the manufacturing of child products, and in France and Canada from all the materials in direct contact with food. The necessity to develop new epoxy resins results therefore urgent.Bio-derived molecules since now developed show the most various chemical structure, each of them producing different properties of final polymers. Peculiar characteristic shown by epoxy resins are related to the aromatic structure of its components. Aromatic molecules present in natural feedstock are mainly derived from lignin, one of the principal constituents of natural cell walls. However, to extract aromatic moieties from lignin, difficult and energy consuming processes are required. A valuable replacement of aromatic molecules, easily recoverable from glucose, are furanic molecules; their validity has been supported by several studies. In the light of the above, the work here presented is focused on production of furanic bio-based epoxy resins as potential substitute of DGEBA in can coating industry. The complete cycle of the material has been studied: the synthesis of furanic epoxy monomers and epoxy thermosets, the characterization of their chemical and physical properties (study of curing kinetics, mechanical and thermal properties). Furthermore, the application of bio-based epoxy thermosets as cans internal lining has been evaluated. Experimental results demonstrated that the obtained resins have good potential to be proposed as good alternatives to the traditional BPA-containing epoxy resins
Mealares, Christel. "Oligomères et polymères furaniques conjugués." Grenoble INPG, 1995. http://www.theses.fr/1995INPG0129.
Full textSignoret, Christian. "Réseaux polyuréthannes classiques et contenant des motifs furanniques pour le confinement de déchets radioactifs : relations structure-propriétés." Grenoble INPG, 1989. http://www.theses.fr/1989INPG0088.
Full textGuigo, Nathanaël. "Biomass based materials : polymers, composites and nano-hybrids from furfuryl alcohol and lignin." Nice, 2008. http://www.theses.fr/2008NICE4062.
Full textThis doctoral project has been conducted within the Ecobinders project which aims to develop new binders based on renewable resources such as furfuryl alcohol and/or lignin. Model-free kinetic and chemorheological analysis of furfuryl alcohol polymerisation have highlighted the different rate determing steps and the phase transitions (gelation, vitrification). The VOC’s released during polymerization have been identified. The influence of lignin incorporation on FA polymerization has been studied and oxidized or plasticized lignins have shown improved reactivity. Lab-scale polyfurfuryl alcohol or polyfurfuryl alcohol / lignin resins and thermoset have been elaborated on the basis of kinetic predictions. Evaluation of thermal instability, relaxation behaviour and morphological aspects of these lab-scale thermosets has highlighted a good compatibility between lignin and furanic network. Moreover, a polyfurfuryl alcohol / silica hybrid synthesized via sol-gel process has shown improved thermal performances as the consequence of nanoscales dispersion of silica particles. The quality control on new Ecobinders prototypes has been established. Dynamic aspects of lignin glass transition have been analyzed with multifrequency DSC together with other techniques. The influence of water sorption, thermal annealing, plasticization and fractionation has been considered. New layered silicate nanocomposite has been elaborated with lignin / natural fibres and improved thermal resistance has been shown
Bougarech, Abdelkader. "Nouveaux copolyesters furaniques sulfonés : Synthèse caractérisation propriétés." Thesis, Lyon, INSA, 2014. http://www.theses.fr/2014ISAL0074.
Full textThe research conducted for the preparation of this thesis is devoted to develop a new family of furanic copolyesters incorporating in their structure sulfonated and pyridinic units. This choice is justified mainly by the following three considerations: (i) the presence of sulfonated units in the poly(ethylene-terephthalate) structure gives to this kind of polymer a specific physicochemical properties favoring its use in various industrial sectors in a detergents and in textiles domains (ii) the presence of furanic unit could lead to the biodegradability of these materials (iii) Pyridinic units confer to these polymers an optoelectronic properties (electrical conductivity, photoconductivity and luminescent properties) favoring its use in various applications , in the space and aeronautics fields
Russell, A. E. "The preparation and crosslinking reactions of epoxide polymers bearing pendant furan groups." Thesis, Queen's University Belfast, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.390859.
Full textGoussé, Cécile. "Applications de la réaction de Diels-Alder aux polymères furaniques." Grenoble INPG, 1997. http://www.theses.fr/1997INPG0007.
Full textXiang, Tengfei. "Synthesis and Characterization of Polymeric Schiff Bases from 2,5-Diformylfuran." University of Akron / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=akron1353710697.
Full textMasroua, Antoine. "Hydrolyse sur support polymères des oligo et polysaccharides et synthèse de l'hydroxyméthyl-5 furfural." Lyon 1, 1985. http://www.theses.fr/1985LYO10036.
Full textCoelho, Dora Salomé Correia. "Novel furan polymer materials based on the reversible Diels-Alder reaction." Doctoral thesis, Universidade de Aveiro, 2011. http://hdl.handle.net/10773/3841.
Full textA futura e inevitável escassez dos recursos fósseis, juntamente com o aumento imprevisível dos seus preços, levou, nas últimas décadas, a um aumento impressionante de iniciativas dedicadas não só à procura de fontes alternativas de fornecedores de energia, mas também de produtos químicos e polímeros a partir de fontes renováveis, em particular da biomassa vegetal. Entre estes, os polímeros derivados de monómeros furânicos constituem uma classe única de materiais cujas estruturas podem, em princípio, simular virtualmente os seus homólogos actualmente derivados de recursos fósseis. O anel furânico é uma estrutura heterocíclica com um carácter diénico pronunciado, o que torna-o um dieno particularmente apropriado para a reacção de Diels-Alder (DA) com dienófilos como a maleimida. Um dos aspectos mais relevantes da reacção de DA é a sua reversibilidade em função da temperatura, a qual permite que os aductos sejam facilmente revertidos nos seus precursores por aumento da temperatura (reacção de retro-DA). No caso específico da combinação furano-maleimida, a formação do aducto predomina até cerca de 60ºC, enquanto a reacção inversa é dominante acima de 100ºC. A combinação desta característica da reacção de DA com a química de compostos furânicos pode abrir um novo caminho para a preparação de materiais macromoleculares funcionais com base em fontes renováveis e com aplicações promissoras como auto-reparação e reciclabilidade. O principal objectivo desta Tese, é a síntese e caracterização de novos materiais poliméricos termo-reversíveis, aplicando a reacção de DA a monómeros complementares com estruturas dos tipos furânico (o dieno, designado por A) e de maleimida (o dienófilo, designado por B). A primeira etapa neste trabalho envolveu a síntese, purificação e caracterização de novos monómeros furânicos e de maleimida do tipo AA, A3, BB, B3, AB, AB2, cada um com diferentes grupos separadores das funções reactivas. Posteriormente, estes monómeros foram polimerizados e despolimerizados por ciclos de DA/retro-DA utilizando diferentes combinações. A formação e dissociação de todos os aductos de DA foram seguidas por ambas espectroscopias de UV e RMN de 1H. O primeiro sistema de DA estudado foi uma combinação modelo entre reagentes mono-funcionais (-A+-B), nomeadamente o acetato furfurílico (FA) e a N-metilmaleimida (MM), ambos comercialmente disponíveis. O objectivo desta abordagem foi estudar a cinética e o equilíbrio da formação/dissociação dos aductos de DA e obter indicações sobre as condições mais adequadas a serem usadas na preparação dos correspondentes novos materiais macromoleculares. Além disso, pretendia-se verificar a presença ou ausência de reacções secundárias que poderiam intervir em ambas as vias directa e inversa das reacções, mesmo após vários ciclos. A espectroscopia de UV forneceu informação quantitativa sobre a cinética de formação do aducto através da diminuição progressiva da absorvência máxima a 293 nm correspondente ao grupo maleimida, a diferentes temperaturas (35, 50, 65 ºC) Reciprocamente, a correspondente reacção de retro-DA foi seguida a 90 ºC através do aumento do mesmo pico. A reversibilidade destes sistemas foi verificada com sucesso após uma sequência de ciclos de DA/retro-DA. Adicionalmente, verificou-se que os espectros originaram um ponto isosbéstico, provando que estes sistemas não envolvem quaisquer reacções secundárias. Uma vez que foi usado um excesso de FA, as reacções de DA modelo apresentaram um comportamento cinético de pseudo-primeira ordem, com a constante de velocidade k mais alta (2.1x10-5 dm3mol-1s-1) para T=65 ºC. A correspondente energia de activação foi de 39.0 kJ.mol-1. A reacção de retro-DA seguiu um comportamento de primeira ordem, com constante de velocidade de 1.6x10-6 s-1. A evolução deste sistema por RMN de 1H a 65ºC deu-nos informações mais detalhadas sobre a sua evolução estrutural, ou seja, à medida que a intensidade dos picos atribuídos à formação do aducto aumentaram progressivamente ao longo do tempo, os pertencentes aos reagentes iniciais diminuiram proporcionalmente. O “rendimento final”, calculado após 20 dias à temperatura ambiente, foi de aproximadamente 70%. A reacção de retro-DA foi depois seguida a 90ºC, observando-se tal como na espectroscopia de UV, o deslocamento da reacção no sentido da regeneração dos reagentes de partida. A viabilidade de múltiplos ciclos de DA/retro-DA estabelecidos pela espectroscopia de UV foi igualmente confirmada por RMN de 1H. O passo seguinte envolveu o estudo de um sistema de policondensação linear baseado no crescimento gradual por reacção de DA entre um monómero bisfurânico A-A e um do tipo bismaleimida B-B, seguindo a mesma abordagem que no sistema modelo. O poliaducto linear foi obtido a partir de soluções equimolares dos monómeros, por reacção de DA a 65ºC. O progresso desta polimerização foi seguido por espectroscopia de UV e RMN de 1H e, mais qualitativamente, pelo aumento da viscosidade do meio. A reacção seguiu um comportamento de segunda ordem, com uma constante de velocidade de 9.4x10-6 dm3mol-1s-1, e observou-se novamente um ponto isosbéstico nos dados de UV. Os espectros de RMN apresentaram o padrão esperado, nomeadamente o aumento progressivo dos sinais associados ao aducto e a correspondente diminuição dos grupos furano e maleimida livres. A despolimerização do poliaducto através da reacção de retro-DA foi seguida a 110ºC usando as mesmas técnicas. Os dados de UV mostraram o retorno progressivo da absorção dos grupos de maleimida, seguindo um comportamento cinético de primeira ordem, com constante de velocidade de 2.5x10-6 s-1, até à completa regeneração de ambos os monómeros. Os espectros de RMN providenciaram mais uma vez informação estrutural sobre o progresso da despolimerização, a qual foi acompanhada por uma diminuição progressiva da viscosidade. Adicionalmente, para seguir a retro- DA, adicionou-se um excesso de composto furânico monofuncional, nomeadamente o 2,5-dimetilfurano (DMFu), ao sistema de modo a bloquear as funções maleimida complementares, evitando assim a repolimerização após arrefecimento. Os productos isolados foram então o monómero bisfurânico AA, DMFu que não reagiu e o bisaducto não-polimerizável de BB com DMFu. Este resultado indicou claramente que o polímero foi de facto revertido nos seus monómeros durante a reacção de retro-DA. O terceiro sistema estudado foi outra polimerização linear, seguindo as mesmas condições experimentais que os anteriores, mas com uma estratégia diferente de modo a contornar o problema clássico de assegurar a estequiometria exacta dos monómeros. As estruturas dos monómeros utilizados incorporam ambos os grupos reactivos, i.e, moléculas do tipo A-B. A polimerização prematura destes monómeros intrinsecamente reactivos foi evitada com a protecção do grupo maleimida na forma de um aducto de DA com furano, até a incorporação do substituinte furânico na outra extremidade. Portanto, a policondensação destes monómeros foi iniciada após a desprotecção in situ deste composto mediante aquecimento, seguido de arrefecimento até à temperatura adequada para polimerizar. Os resultados obtidos por UV e RMN sugerem que de facto o uso de monómeros do tipo A-B oferece um melhor sistema linear. Em seguida, foram estudados sistemas de policondensação não-linear por reacção de DA, entre monómeros (um ou ambos) com funcionalidade superior a dois, nomeadamente sistemas do tipo A3+B-B ou A-A+B3, seguindo mais uma vez as mesmas condições experimentais. Uma vez que utilizam monómeros complementares contendo, em média, mais de duas funcionalidades, estes sistemas conduzem a materiais reticulados. Nestes estudos, foram usadas três razões molares de [maleimida]/[furano], nomeadamente 1.0, 0.75 e 0.5, de modo a estudar ambas as situações de não-gelificação e reticulação. Ambos sistemas apresentaram um comportamento regular e boa reciclabilidade quer para gerar situações que possam conduzir à formação de redes a diferentes graus de conversão, ou que possam parar antes da sua obtenção, conforme previsto pela equação de Flory-Stockmayer. Como esperado, a utilização de grupos complementares em quantidades estequiométricas produziu o espessamento mais rápido e a reticulação quase completa; à medida que a quantidade relativa de monómero trifuncional decresceu, as reacções pararam antes da reticulação, ou seja, originaram meios altamente viscosos contendo polímeros solúveis altamente ramificados. As reacções de retro-DA a 110 ºC conduziram à gradual dissolução das partículas de gel (quando presentes), tendo sido comprovado pelos espectros de UV e de RMN de 1H, evidenciado a regeneração dos monómeros. Tal como no sistema do tipo A-A+B-B, a reacção de retro-DA foi seguida adicionando um excesso de DMFu ao sistema reaccional. Como esperado, os produtos finais foram os monómeros furânicos, o DMFu em excesso e o trisaducto ou o bisaducto maleimida-DMFu, o que confirma a eficiência da despolimerização com regeneração dos monómeros iniciais. O último sistema de policondensação por reacção de DA envolveu um monómero assimetricamente substituído do tipo AB2, capaz de originar estruturas macromoleculares hiper-ramificadas que não reticulam. Este estudo preliminar deste sistema foi seguido nas mesmas condições experimentais que os anteriores, apresentando um comportamento com as características esperadas.
The inevitable future scarcity of fossil resources, together with their skyrocketting prices, has led in the last decades to a dramatic increase of initiatives devoted not only to the search for alternative sources of energy providers, but also to the search for chemical commodities and polymers from renewable resources, namely the vegetable biomass. Among these, polymers from furan monomers constitute a unique class of materials whose structures can in principle simulate virtually all their current fossil-derived counterparts. The furan heterocycle displays a pronounced dienic character, which makes it highly suitable as diene in the Diels-Alder (DA) reaction, with dienophiles like maleimide. One of the most relevant aspects of the DA reaction is its thermal reversibility, which allows the adducts to be readily reverted to their precursors as the temperature is raised (retro-DA reaction). In the specific case of the furan-maleimide combination, the adduct formation dominates up to ca. 60ºC, whereas the reverse reaction is overwhelming above ca. 100ºC. The coupling of this DA feature with the furan chemistry can open a new way to prepare functional macromolecular materials based on renewable resources with novel properties and promising applications like mendability and recyclability. In this Thesis, the main goal is the synthesis and characterisation of novel thermoreversible polymer materials by means of the DA reaction, using complementary monomers bearing furan (the diene, assigned as A) and maleimide (the dienophile, assigned as B) moieties. The first step in this study was the synthesis, purification and characterization of new furan and maleimide monomers, viz. AA, A3, BB, B3, AB, AB2, each bearing different spacing moieties separating the reactive functions. They were then polymerized and depolymerised using different modes of DA/retro-DA cycles. The formation and decoupling of all the DA adducts were followed by both UV and 1H NMR spectroscopy. The first DA system investigated was on a model combination of monofunctional reagents (-A+-B), namely the commercially available furfuryl acetate (FA) and N-methylmaleimide (MM). The purpose of this approach was to study the kinetics and the equilibrium of the formation/decoupling of the DA adducts and to provide clear indications about the most appropriate conditions to be applied in the preparation of the corresponding novel macromolecular materials. Additionally, it aimed at verifying that no detectable side reactions intervened in both forward and backward pathways, even after several cycles. The UV spectroscopy provided quantitative information on the kinetics of the DA adduct formation by monitoring the progressive decrease in the maximum absorbance at 293 nm related to the maleimide moiety, at different temperatures (35, 50, 65ºC). Conversely, the corresponding retro-DA reaction was followed at 90ºC through the increase of the same peak. The reversibility of these systems was successfully checked over a couple of cycles. Additionally, all set of spectra gave rise to an isosbestic point, which proved that these systems did not involve any side reactions.Since an excess of FA was used here, these model DA reactions displayed a pseudo-first order behaviour, with the highest rate constant k (2.1x10-5 M-1.s-1) for T= 65ºC. The corresponding activation energy was found to be 39.0 kJ.mol-1. The retro-DA reaction followed a first order behaviour, with a rate constant of 1.6x10-6s-1.The evolution of the same system followed by 1H NMR spectroscopy at 65ºC gave a detailed insight into its structural evolution, viz. as the intensity of the peaks assigned to the adduct formation progressively increased with time, those belonging to the initial reagents decreased correspondingly. The “final yield” taken after 20 days at room temperature, was approximately 70%. The retro- DA reaction was then carried out at 90ºC, and showed the same features as its UV counterparts, namely the displacement of the reaction towards the regeneration of the initial reagents. The feasibility of multiple DA/retro-DA cycles established by UV spectroscopy was confirmed here. The subsequent stage involved the study of a linear polycondensation system based on the stepwise DA growth between a difuran monomer A-A and a complementary bismaleimide B-B, following the same approach as the model system. The formation of the linear DA polyadduct was achieved by letting equimolar solutions evolve at 65 ºC. The progress of this polymerization was followed by UV and 1H NMR spectroscopy and, more qualitatively, by the increase in the viscosity of the medium. The reaction followed a second order behaviour, with a rate constant of 9.4x10-6 M-1.s-1, and again, a characteristic isosbestic point was observed in the UV data. The NMR spectra gave the expected pattern, namely the progressive increase in the signals associated with the adduct and the corresponding decrease of those attributed to the unreacted furan and maleimide cycles. The depolymerization of the polyadduct through the retro-DA reaction was followed at 110ºC by the same techniques. The UV time scans showed the progressive return of the absorption due to maleimide moieties following a first-order kinetic pattern, with a rate constant of 2.5x10-6 s-1, until both monomers were fully regenerated. The 1H NMR spectra provided once more structural information about the course of this depolymerization, which was accompanied by a progressive decrease in viscosity. Additionally to follow the retro-DA, an excess of a monofunctional furan compound, namely 2,5-dimethylfurfural (DMFu), was added to the system in order to block the complementary maleimide functions, thus avoiding the repolymerisation after cooling. The isolated products were then the difuran monomer AA, the unreacted DMFu and the non-polymerizable bisadduct of BB with DMFu. This result clearly indicated that the polymer had indeed reverted to its monomers during the retro-DA. The third system studied was another linear polymerization, following the same experimental conditions as the previous, but with a different strategy, in order to avoid the classical problem of ensuring the exact monomer stoichiometry. Here, the monomers incorporated both reactive moieties in their structures, i.e. A-B molecules. Here, the premature polymerization of these intrinsically reactive monomers was avoided by protecting the maleimide group in the form of a furan-DA adduct, until the incorporation of the furan moiety. Therefore, the polycondensation of these monomers was initiated after the in situ deprotection of this compound through heating, followed by the cooling to appropriate temperature for polymerization. The results obtained by both UV and NMR spectroscopy suggested that indeed the use of an A-B monomer provides a better linear system. Non-linear DA polycondensations between monomers (one or both) with functionality higher than two, viz. A-A+B3 or A3+B-B systems, were then studied, following once more the same experimental conditions. The use of complementary monomers bearing on average more than two functionalities lead to crosslinked materials. In these systems, three [maleimide]/[furan] molar ratios, viz. 1.0, 0.75 and 0.50, were applied in order to examine both nongelling and crosslinking situations. Both types of systems displayed a clean-cut behaviour and good recyclability to generate situations either leading to the formation of a network at different degrees of conversions, or ending before its attainment, as predicted by the Flory-Stockmayer equation. As expected, the use of complementary moiety stoichiometry produced the most rapid thickening and near-complete crosslinking, whereas as the relative amount of trifunctional monomer was decreased, the reactions stopped short of crosslinking, i.e. gave highly viscous media containing soluble highly branched polymers. The retro-DA reactions at 110ºC revealed the gradual dissolution of the gel particles (when present), while the UV and 1H NMR spectra gave, once more, the details of the depolymerization processes leading the systems steadily back to the monomers. As in A-A+B-B depolymerization, to follow the retro-DA, an excess of DMFu DA trap, was added to the systems under the same conditions. As expected, the final products were the furan monomers, the unreacted DMFu and the non-polymerizable trisadduct or the bisadduct of maleimide-DMFu, confirming the efficiency of the retro-DA depolymerisation in the regeneration of the starting monomers. The last DA polycondensation system involved an assymmetrically substituted monomer of the AB2 type, capable of generating hyperbranched macromolecular structures that do not crosslink. This preliminary study was followed by the experimental approach applied above and the behaviour of the system displayed the expected features.
POCTI; FCT; FSE - SFRH/BD/28271/2006
Marref, Mohamed. "Synthèse et caractérisations de réseaux thermosensibles à base époxy / amine par réactions de Diels-Alder." Phd thesis, Université Jean Monnet - Saint-Etienne, 2013. http://tel.archives-ouvertes.fr/tel-01004162.
Full textMuralidhara, Anitha. "Physico-chemical safety issues pertaining to biosourced furanics valorization with a focus on humins as biomass resource." Thesis, Compiègne, 2019. http://www.theses.fr/2019COMP2508.
Full textThe present research work was integrated as part of the EU-funded project named HUGS (HUmins as Green and Sustainable precursors for eco-friendly building blocks and materials), involving 5 main partners (Institut national de l'environnement industriel et des risques - France, Avantium - the Netherlands, Institut de Chimie de Nice - France, Universidad De Cordoba- Spain and Leibniz - Institut Fur Katalyse Ev An Der Universitat Rostock- Germany). The project is essentially supported through five European Industrial Doctorate fellowships put in place when the HUGS-MSCA-ITN-2015 program was launched in 2016. The primary objective of the HUGS project was to explore several valorization pathways of so-called “humins” in order to add value and create better business cases. Humins (and similarly lignins) are the side products that may become low-cost feedstock resulting from a number of future biorefineries and sugar conversion processes. Humins are complex residues resulting from the Acid-Catalyzed Dehydration and condensation of sugars, having furan-rings in their polymeric structures. The work presented in this specific part of the HUGS project is essentially focusing on safety-related topics of all components and subsequent applications related to sugar dehydration technology. Priority actions were devoted to a first insight on the characterization of physicochemical safety profiles of the side-product humins and main (parent) furanic products. Some members of this large family of compounds (e.g. RMF and FDCA) have high volume potential which results in opening new doors towards the development of furanbased building blocks and a bio-based economy. Humins are residues or side products which can be burnt for energy. However, its safe and sustainable use in high-value applications could also become a key milestone in the so-called circular economy. In practice, the work has been developed in two main locations: primarily at the INERIS lab, located in Verneuil-en-Halatte and at Avantium, located in Amsterdam. Nearly all experimental research after the production of the components at Avantium was performed at INERIS. This involved the evaluation of physicochemical hazards of both humins (crude industrial humins and humin foams obtained by thermal curing) and a series of furanic compounds. Avantium is involved in the commercialization of humins, furanics and furanic polymers/materials as novel chemicals and materials. The work has encompassed: An extensive bibliographical review of humins, furanics, and their related products (polymers, composites) resulted in the following main conclusions o A lack of physicochemical safety-oriented studies for many furanic compounds and for humins was observed as these products are still in the early stage of development and only a few may be commercialized in the next 5 years.o Despite the limited availability of safety-related data, more studies on toxicity aspects have been conducted for a selected number of furanics than physicochemical safety-related aspects. o A few furanic family members that have been evaluated as biofuel components were found to have given better emphasis on addressing some physicochemical safety attributes. o Every modification of the process for acid-catalyzed sugar dehydration (such as solvent, temperature, residence time and sugar concentration) will result in different humins, which would certainly demand further characterization and safety profiling of the resulting humins. • Analytical development integrating the first examination of flash point distribution versus the Net Heating Values, and analysis of total heats of combustion of furanic compounds. • Design and development of experimental plan addressing the safety-related key parameters such as thermal stability, self-heating risks, fire-risk-assessment and flammability limits depending on the need for specific tests and availability of the test samples
Höhne, Susanne. "Untersuchungen zur kationischen Polymerisation von Vinylmonomeren des Furans und Thiophens." Doctoral thesis, Universitätsbibliothek Chemnitz, 2006. http://nbn-resolving.de/urn:nbn:de:swb:ch1-200501585.
Full textThe following work examines the cationic polymerization of the heterocyclic monomers 2-vinylfuran, 5-methyl-2-vinylfuran und 2-vinylthiophen mediated by silica particles. The products of this reaction are polymer/SiO2-hybridpartikels and a soluble polymer part. For characterization of the products NMR-spectroscopical methods, IR-, UV/Vis-, MALDI TOF-spectroscopy, elemental analysis and GPC were used. With the help of this methods it succeeded to clear up the polymer structure. The influence of the reaction conditions on the results of the cationic polymerization was examined and discussed. Extensive crosslinking of the 2-vinylfuran monomer during cationic polymerization causes a very strong linkage of the poly(2-vinylfuran)-layer and a hight polymer content of the poly(2-vinylfuran)/SiO2-hybridpartikels. In case of poly(2-vinylthiophen) (PVT) the polymer content of the hybrid particles was notedly lower. A linear polymer structure was supposed. The reaction of poly(2-vinylthiophen) and poly(2-vinylthiophen)/silica hybrid particles with hydridacceptors and FeCl3 was studied. The objectives of this reactions were to generate conjugated structures and to cross-link the polymer by creating bisthiophene structures in a controlled manner. The influence of the reaction time and the nature of the acceptors on the reaction of PVT with the hydride acceptors was examined in detail. The influence of the reaction conditions on the cross-linking reaction with FeCl3 was studied with the help of GPC, IR- und 13C{1H} CP/MAS NMR spectroscopy
Benahmed-Gasmi, Amina. "Nouveaux précurseurs de matériaux organiques conducteurs : des donneurs-pi aux polymères conjugués." Angers, 1996. http://www.theses.fr/1996ANGE0020.
Full textThomas, Jaron Michael. "On Metal synthesis of Some Substituted Rhenium and Manganese Complexes." TopSCHOLAR®, 2012. http://digitalcommons.wku.edu/theses/1225.
Full textTournadre-Lasseuguette, Elsa. "Elaboration de nouveaux polymères photosensibles furaniques en vue de leur application sur plaques offset." Phd thesis, Grenoble INPG, 2004. http://tel.archives-ouvertes.fr/tel-00007623.
Full textUllmann, Robert. "Oberflächenfunktionalisierung von Poly(dimethyl)siloxan." Doctoral thesis, Universitätsbibliothek Chemnitz, 2013. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-107389.
Full textMatos, Marina da Conceição da Silva. "Development of more sustainable polymers and composites materials based on 2,5-furandicarboxylic acid." Doctoral thesis, 2019. http://hdl.handle.net/10773/25789.
Full textNos dias de hoje, os problemas ambientais, as mudanças climáticas, os recursos fósseis limitados e sua flutuação de preço, associados à atividade industrial (muitas vezes muito pouco ecológicas) são as forças motrizes para governos, empresas e cientistas encontrarem alternativas para os materiais preparados a partir de recursos fosséis. Neste cenário, o ácido 2,5- furandicarboxílico (FDCA), em produto químico de origem renovável, surgiu como o substituto mais promissor do ácido tereftálico na síntese de diversos materiais, particularmente poliésteres, que possuem propriedades térmicas e mecânicas semelhantes. Estes materiais podem ser utilizados nas aplicações existentes, e em outras novas aplicações, inovadoras e de alto valor. Neste contexto, o desenvolvimento de polímeros e materiais sustentáveis a partir dos furanos é oportuno e bastante relevante. Precisamente, esta tese tem como principal objetivo o desenvolvimento polímeros e materiais compósitos mais sustentáveis a partir do FDCA e uma panóplia de compostos alifáticos selecionados pela sua origem renovável. Posteriormente, foi ainda avaliado o potencial de um novo monómero éster preparado a partir do FDCA como plastificante para a substituição parcial do não renovável tereftalato de di(2- etilhexilo) em formulações de cloreto de polivínilo (PVC). No primeiro estudo, foi preparado um poliéster parcialmente renovável a partir do FDCA e do 1,4-ciclohexanodiol, nomeadamente o poli(2,5- furanodicarboxilato de 1,4-ciclohexileno) (PCdF) com o objectivo de se obter um novo material com propriedades térmicas melhoradas. A sua síntese foi efetuada a partir de duas abordagens distintas, nomeadamente via policondensação em solução e politransesterificação em estado sólido. Por motivos comparativos, foi ainda sintetizado o homopolímero poli(2,5- furandicarboxilato de 1,4-ciclohexanodimetileno) (PCF), devido à semelhança estrutural entre ambos. Homopolímeros com pesos moleculares diferentes foram obtidos de acordo com a abordagem de síntese e catalisadores utilizados (valores de Mn e Ð variando entre 4 300-14 100 g/mol e 1.2-1.7, respetivamente). Os materiais resultantes revelaram possuir carácter semi-cristalino com elevadas temperaturas de transição vítrea (valores de Tg de 175 e 105 ºC, para o PCdF e PCF, respetivamente) e estabilidade térmica até aos 377 ºC. Verificouse ainda que, a ausência do grupo metileno no homopolímero PCdF, deu origem a um material com estrutura de cadeia polimérica mais rígida, e consequentemente um valor de Tg mais elevado. Num segundo estudo, vários copolímeros do poli(2,5-furanodicarboxilato de 1,4- butileno)-co-poli(2,5-furanodicarboxilato de poli(óxido de propileno)) (PBF-co- PPOF) poli(éster-éter)s foram sintetizados a partir do 2,5-furanodicarboxilato de dimetilo e diferentes rácios molares do 1,4-butanodiol e do poli(óxido de propileno. Os copolímeros resultantes apresentaram caráter semi-cristalino quando quantidades superiores de PBF foram usadas, líquidos viscosos completamente amorfos quando o rácio PBF/PPOF usado foi igual a 1. Mais ainda, estes materiais apresentaram elevada estabilidade térmica (temperaturas de degradação máxima entre 340-365 ºC, e baixas Tg´s (valores a variar entre os - 42.3 a -32.6 ºC), facilitando desta forma o seu processamento a mais baixas temperaturas. Adicionalmente, num terceiro estudo, abrangendo a preparação de uma série de nanocompósitos à base de FDCA, preparados usando os copolímeros poli(2,5-furanodicarboxilato de 1,4-butileno)-co-poli(diglicolato de 1,4-butileno) (PBF-co-PBGD e celulose bacteriana acetilada (Ac-BC). Numa primeira etapa, os copolímeros foram sintetizados; seguida da preparação de filmes de nanocompósitos, obtidos através da abordagem de evaporação de solvente. Curiosamente, para uma maior incorporação de unidades de BDG, estes materiais reforçados demonstraram um aumento de rigidez (módulo de Young até 1239 MPa) e elasticidade aceitável (valores alongamento até à ruptura entre 0.6 até 25.0 %) quando comparados com os seus (co)polímeros homólogos puros. Além disso, foram observados valores similares para as permeabilidade ao oxigénio dos nanocompósitos e (co)polímeros, expandindo a exploração destes materiais para aplicações como embalagens. Finalmente, um quarto estudo, abordou a possibilidade de usar um éster furânico como aditivo para formulações de poli(cloreto de vinilo) (PVC) (Capítulo VI). A combinação dos plastificantes 2,5-furanodicarboxilato de di(2-etilhexilo) (DEHF) com o tereftalato de di(2-etilhexilo) (DEHT) foi efetuada de forma a aumentar o ‘conteúdo verde’ das formulações de PVC. Estes materiais demostraram possuir maior compatibilidade com a matriz do PVC comparativamente com os preparados apenas com o DEHF. Mais ainda, apresentaram características térmicas comparáveis aos preparados apenas com o DEHT (Tg’s entre 19.2 e 23.8 ºC) e um aumento do alongamento até à rutura (até 330%). Além disso, os testes de migração revelaram muito baixas percentagens de perda de massa, não excedendo os 0.3% e os 0.2%, respetivamente, para a água e para a solução PBS. Mais importante, resultados preliminares em testes de viabilidade celular in vitro (concentrações até 500 μM e máximo de 72 h) revelaram um perfil não-tóxico para ambos os plastificantes, DEHF e DEHT. Todos os materiais e químicos preparados a partir do FDCA dentro do âmbito desta dissertação são uma importante contribuição para a crescente procura por novos materiais de origem renovável, dentro de uma abordagem sustentável. Mais, estes materiais e químicos apresentaaram propriedades semelhantes ou melhoradas às dos preparados a partir de recursos petrolíferos.
Programa Doutoral em Química Sustentável
Chou, Chih-Ming, and 周志明. "Furan-Containing Oligoaryls and Polymers: Synthesis and Photophysics." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/83899260065612216854.
Full text臺灣大學
化學研究所
96
A range of oligoaryls having alternating para- or meta-benzene-furan rings is synthesized by rapid convergent/divergent method from the annlation of a propargylic dithioacetal and an aldehyde having a propargylic dithioacetal moiety as the substituent. This route provides a useful procedure toward the synthesis of monodisperse oligoaryls without repetitive units. Systematic investigation on the photophysical properties and molecular folder phenomenon of these oligomers are also explored. A series of dithiolated alternating benzene-furan oligoaryls was synthesized. IRAS (infrared reflection-absorption spectroscopy) and STM (scanning tunneling microscopy) experiments revealed that single-component monolayers of these oligoaryls have lattice packing of crystalline by pi-pi interaction and each distance between two single molecules is about 0.51 nm. The conductance of single molecule was decreased with the conjugated length of alternating benzene-furan oligoaryls increased. In addition, a series of double stranded polymers by using furan-containing oligoaryls as linkers was synthesized. Conformational change of the norbornene moiety after ROMP (ring opening metathesis polymerization) lead chormophores aggregated and quenched the fluorescent intensity. The first oxidation potential of polymers were conformably lower than corresponding monomers, and the difference of first oxidation potential between monomer and polymer was increased with the conjugated length of chormophores increased.
Chang, Che-Yuan, and 張哲淵. "Synthesis and properties of benzoxazine containing fluorene and furan groups and their corresponding polymers." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/54697673768839857309.
Full text中原大學
化學工程研究所
99
In this study,a novel benzoxazine monomer FDP-FBz was synthesized using furfurylamine, formaldehyde and 4,4’-(9-Fluorenylidene) diphenol(FDP) as reactants. The chemical structure of 9,9-Bis(3- furfuryl-3,4-dihydro-2H-1,3- benzoxazinyl)fluorine (FDP-FBz) was characterized with FT-IR, 1H-NMR amd elemental analysis, proving that we synthesized high-purity FDP-FBz monomer successfully. First part, PFBz possessing benzoxazine group in the mainchain was prepared through the Diels-Alder reaction using FDP-FBz and 1,1’-(Methylenedi-4,1-phenylene) bismaleimide (DDM-BMI) as monomers. After thermal ring opening polymerziation, poly(PFBz) showed a high Tg at 360℃, and good thermal stability. Second part, two kind of hyperbranched polymers, TMI-BFBz and TMI-FFBz were prepared from bis(3- furfuryl-3,4-dihydro-2H-1,3-benzoxazinyl) isopropane(BPA-FBz) and Trimaleimidophenyl phosphine oxide(TMPPO), FDP-FBz and TMPPO as monomer, respectively. After thermal ring opening polymerziation, poly(TMI-BFBz)and poly(TMI-FFBz) showed high Tgs at 350℃ and 330 ℃, respectively, and good thermal stability.
Jeng, Shwu-Huey, and 鄭淑慧. "A Liquid Crystalline Polysiloxane Polymer as Stationary Phase in Gas Chromatography Capillary Column for Separation theDioxin/furans Compounds." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/85281853458904283015.
Full text高雄醫學大學
職業安全衛生研究所
88
A side chain liquid crystalline polysiloxane polymer(PS3DBDE1) with high purity and high isotropic transition temperature served as a stationary phase in an attempt to chromatographize the dioxin/furan compounds. The polymer was coated on the inner surface of a 0.25(i.d.) capillary column by using the static coating method, forming a film with its thickness of df 0.25 m. A commercial standard solution (US EPA1613 standard solution 1613CS4) containing polychlorinated dibenzo-p-dioxins(PCDDs) and polychlorinated dibenzofurans(PCDFs) was used to test the chromatographic behavior of homemade capillar column. Two commerical capillary columns HP-5MS(Hewlett-Packard Co.) and RTX-5MS(RTX Co.) were choosen to compare their chromatographic behavior. The results show that the isomeric pair compounds 1,2,3,4-TCDD vs 2,3,7,8-TCDD and 1,2,3,4,7,8-HxCDD vs 1,2,3,6,7,8-HxCDD and the same substituted-chlorine number compounds 1,2,3,4,6,7,8-HpCDF vs 1,2,3,4,6,7,8-HpCDD and 1,2,3,4,6,7,8,9-HpCDD vs 1,2,3,4,6,7,8,9-HpCDF had higher resolution than HP-5MS(Hewlett-Packard Co.) and RTX-5MS(RTX Co.) suggested by the column makers.
Höhne, Susanne. "Untersuchungen zur kationischen Polymerisation von Vinylmonomeren des Furans und Thiophens." Doctoral thesis, 2005. https://monarch.qucosa.de/id/qucosa%3A18406.
Full textThe following work examines the cationic polymerization of the heterocyclic monomers 2-vinylfuran, 5-methyl-2-vinylfuran und 2-vinylthiophen mediated by silica particles. The products of this reaction are polymer/SiO2-hybridpartikels and a soluble polymer part. For characterization of the products NMR-spectroscopical methods, IR-, UV/Vis-, MALDI TOF-spectroscopy, elemental analysis and GPC were used. With the help of this methods it succeeded to clear up the polymer structure. The influence of the reaction conditions on the results of the cationic polymerization was examined and discussed. Extensive crosslinking of the 2-vinylfuran monomer during cationic polymerization causes a very strong linkage of the poly(2-vinylfuran)-layer and a hight polymer content of the poly(2-vinylfuran)/SiO2-hybridpartikels. In case of poly(2-vinylthiophen) (PVT) the polymer content of the hybrid particles was notedly lower. A linear polymer structure was supposed. The reaction of poly(2-vinylthiophen) and poly(2-vinylthiophen)/silica hybrid particles with hydridacceptors and FeCl3 was studied. The objectives of this reactions were to generate conjugated structures and to cross-link the polymer by creating bisthiophene structures in a controlled manner. The influence of the reaction time and the nature of the acceptors on the reaction of PVT with the hydride acceptors was examined in detail. The influence of the reaction conditions on the cross-linking reaction with FeCl3 was studied with the help of GPC, IR- und 13C{1H} CP/MAS NMR spectroscopy.
Gengan, Robert Moonsamy. "A study to identify a feasible route for the production of the monomer 2-vinylfuran from furan by evaluating the effect of variables on the final yield and to recommend suitable conditions applicable to the chemical industry." Thesis, 1992. http://hdl.handle.net/10321/2754.
Full text2- Vinylfuran has been synthesised from furan, obtained from furfural a degradation product of bagasse, and has the potential to be used as a monomer in the Polymer Industry. Furan was successfully reacted with ethylene under catalytic conditions of palladium (II) acetate and copper (II) acetate to produce 2-vinylfuran, via a direct substitution reaction, at atmospheric pressure and a temperature of 9Y C for two hours in dimethylformamide.
M
Ullmann, Robert. "Oberflächenfunktionalisierung von Poly(dimethyl)siloxan." Doctoral thesis, 2012. https://monarch.qucosa.de/id/qucosa%3A19852.
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