Rozprawy doktorskie na temat „Matières plastiques biodégradables – Environnement”
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Deroiné, Morgan. "Étude du vieillissement de biopolymères en milieu marin". Electronic Thesis or Diss., Lorient, 2014. http://www.theses.fr/2014LORIS354.
Pełny tekst źródłaPollution of nature by plastics is a major environmental problem and better management of the lifetime of polymers is a major challenge for the future. In recent years, bio-based and biodegradable polymers, such as polylactide (PLA), or polyhydroxyalkanoates (PHA) have appeared as an alternative solution in order to solve these problems. One of the limits remains the relative lack of knowledge of their lifetime and degradation behaviour in aqueous environments, and more specifically in the marine environment. In this study natural and accelerated ageing tests were performed under several conditions, distilled water, filtered and renewed seawater and natural seawater, at different temperatures, in order to decouple enzymatic and hydrolytic mechanisms. The aim of this study is to establish a baseline on degradation mechanisms and kinetics, in order to make lifetime predictions of biopolymer behaviour in seawater.Degradation phenomena have been identified. Biodegradation tests were also performed in a marine environment by following the release of CO2. Then, lifetime predictions of the properties of these biopolymers at seawater temperature were made using two different approaches
Deroiné, Morgan. "Étude du vieillissement de biopolymères en milieu marin". Thesis, Lorient, 2014. http://www.theses.fr/2014LORIS354/document.
Pełny tekst źródłaPollution of nature by plastics is a major environmental problem and better management of the lifetime of polymers is a major challenge for the future. In recent years, bio-based and biodegradable polymers, such as polylactide (PLA), or polyhydroxyalkanoates (PHA) have appeared as an alternative solution in order to solve these problems. One of the limits remains the relative lack of knowledge of their lifetime and degradation behaviour in aqueous environments, and more specifically in the marine environment. In this study natural and accelerated ageing tests were performed under several conditions, distilled water, filtered and renewed seawater and natural seawater, at different temperatures, in order to decouple enzymatic and hydrolytic mechanisms. The aim of this study is to establish a baseline on degradation mechanisms and kinetics, in order to make lifetime predictions of biopolymer behaviour in seawater.Degradation phenomena have been identified. Biodegradation tests were also performed in a marine environment by following the release of CO2. Then, lifetime predictions of the properties of these biopolymers at seawater temperature were made using two different approaches
Peyrat, Eric. "Nouveau composite biodégradable obtenu à partir de maïs plante entière : étude du procédé de transformation thermo-mécano-chimique en extrudeur bi-vis et de la mise en forme par injection-moulage". Toulouse, INPT, 2000. http://www.theses.fr/2000INPT100G.
Pełny tekst źródłaBidoret, Aurélie. "Protection par encapsulation de l’enzyme lors de l’incorporation dans des plastiques biodégradables". Nantes, 2016. http://www.theses.fr/2016NANT079F.
Pełny tekst źródłaThe development of biodegradable plastics by incorporating of enzymes is one of the potential solutions to the growing problems of domestic and industrial wastes. The objective of this thesis is to develop four existing encapsulation methods providing protection for the enzymes used in biodegradable plastics. The first method consist of forming polylacticacid (PLA) microspheres by using encapsulation by solvent evaporation
Cazaudehore, Guillaume. "Méthanisation des plastiques biodégradables : performances et diversité microbienne". Electronic Thesis or Diss., Pau, 2022. http://www.theses.fr/2022PAUU3002.
Pełny tekst źródłaGrowing concern regarding non-biodegradable plastics and the impact of these materials on the environment has promoted interest in biodegradable plastics. Biodegradable plastics offer additional waste management options (e.g., anaerobic digestion or composting) over conventional plastics. However, the treatment of biodegradable plastics under anaerobic digestion is only in its infancy. Therefore, the aim of this thesis was to investigate the fate of biodegradable plastics in anaerobic digestion systems and the microorganisms involved in the plastic conversion to methane.For this purpose, batch anaerobic digestion experiments were performed on the main biodegradable polymers and on three commercial blends of biodegradable polymer, under both mesophilic and thermophilic conditions. Only Poly(3-hydroxybutyrate) (PHB) and Thermoplastic starch (TPS) exhibited rapid (25-50 days) and important (57-80.3% and 80.2-82.6%, respectively) conversion to methane under both mesophilic and thermophilic condition. Methane production rates from poly(lactic acid) (PLA) was very low under mesophilic condition, to such an extent that 500 days were required to reach the ultimate methane production, corresponding to a PLA conversion to methane of 74.7-80.3%. Methane production rate from PLA was greatly enhanced under thermophilic condition since only 60 to 100 days were required to reach the same ultimate methane production. Lactate-utilizing bacteria such as Tepidimicrobium, Moorella and Tepidanaerobacter were revealed to be important during the thermophilic digestion of PLA. Similarly, starch-degrading bacteria (from Clostridium genus) were highlighted during TPS digestion at 38 °C and 58°C. Previously known PHB degraders (i.e., Enterobacter, Ilyobacter delafieldii and Cupriavidus) were observed during mesophilic and thermophilic AD of PHB. The low biodegradation rate of most of the biodegradable plastics in mesophilic anaerobic digesters is a major hindrance to their introduction at industrial scale. Thermal (at 120 or 150 °C) and thermo-alkaline (at 70°C or 90 °C with calcium hydroxide addition) pretreatments were successfully implemented on PLA. These strategies were tested on PLA, which is one of the main biodegradable polymer, accounting for 25% of the biodegradable plastic production. PLA pretreated with these treatments, achieved biodegradation yield of 73% after 15-20 days; a similar biodegradation yield was obtained after 500 days for untreated PLA.PHB and PLA are among the most studied polymer to replace conventional plastics. Finally, the stability and performances of the co-digestion of these plastics (with and without PLA pretreatment) with food wastes fed semi-continuously under mesophilic conditions was investigated. The addition of biodegradable plastics resulted in a more stable process (in comparison with stand-alone biowastes reactor) and no negative effects could be detected. PHB was estimated to be fully biodegraded in the reactors. By contrast, PLA was accumulating in the reactor, and an average biodegradation of 47.6% was estimated during the third hydraulic retention time. Thermo-alkaline pretreatment of PLA improved the biodegradation yield of PLA to 77.5%. The identification of specific microorganisms implicated in the biodegradable plastic degradation was complicated; the majority of the microorganisms correlated with the methane production from reactors co-digesting PLA and PHB were implicated in the anaerobic digestion of the biowaste, which can be explained by the low proportion of biodegradable plastics introduced
Jacob-Vaillancourt, Colin. "Caractérisation avancée et valorisation des plastiques mélangés postconsommation : étude de cas chez Gaudreau Environnement inc". Master's thesis, Université Laval, 2018. http://hdl.handle.net/20.500.11794/28305.
Pełny tekst źródłaLes plus récents estimés indiquent que seulement 32% des plastiques post-consommation (emballages, sacs et contenants) sont récupérés par la collecte sélective des matières recyclables au Québec, et une quantité probablement encore moindre est réellement recyclée. Pourtant, le recyclage a été identifié comme une des stratégies clés permettant la mise en place d’une véritable économie circulaire des plastiques. Présentement, un manque de données précises et transférables entre les acteurs de la chaîne de valeurs rend plus difficile l’application de mesures efficaces pour augmenter la qualité des plastiques voués au recyclage thermomécanique. De plus, il existe peu de solutions de recyclage pour les flux de plastiques fortement hétérogènes, alors que la diversité des emballages disponibles sur le marché est sans cesse croissante. Ce travail de recherche avait pour objectif d’étudier la qualité des plastiques mélangés en provenance du centre de tri de Gaudreau Environnement Inc., et de développer une technologie de recyclage applicable aux flux hétérogènes de plastiques. Une caractérisation combinant des équipements industriels et des analyses de laboratoire a permis de dégager un taux de qualité correspondant à la concentration réelle d’un polymère visé dans un échantillon trié par séparateur optique. De plus, la caractérisation des contaminants a démontré que les plastiques faits de polystyrène et de polyvinyle chloré sont sujets à de grandes variations de qualité. Une méthode de recyclage de ces plastiques est proposée ici, soit l’utilisation d’agrégats de plastiques recyclés comme substituts au sable pour des mélanges expérimentaux de béton. Le plastique a généré des bétons ayant une plus grande ténacité élastique et une résistance thermique plus élevée que le béton conventionnel. Cette technique de recyclage a semblé convenir aux flux hétérogènes de plastiques, notamment lorsque plusieurs types de polymères sont présents, car les critères de qualité diffèrent de ceux employés pour évaluer les plastiques voués au recyclage thermomécanique conventionnel.
According to recent estimates, only 32% of all postconsumer plastics are collected by curbside collection programs in the province of Quebec (CANADA), and an even smaller amount may be actually recycled into new products. Recycling has nonetheless been identified as one of the key strategies needed to enable a transition to a fully circular economy for plastics. At this time, a lack of precise data, transferable between all stakeholders of the plastics value chain, prevents the implementation of efficient measures to upgrade the quality of plastics channelled towards thermomechanical recycling. Also, very few recycling techniques are designed for heterogeneous plastic streams, while an increasingly varied array of plastic packaging is found on the consumer market. This research aimed to study the quality of a mixed plastics stream produced by Gaudreau Environnement Inc.’s material recovery facility, and develop a recycling technique able to process an heterogeneous plastic stream. A combination of industrial machineries and laboratory analyses was used to characterize the quality of the mixed plastics, and a quality index was generated to estimate the concentration of a targeted polymer in a sorted plastic stream. A characterization of contaminants showed that polystyrene and polyvinyl chloride streams experienced more variation in terms of quality for recycling. A potential valorization route was investigated, where recycled plastic aggregates were substituted to sand in experimental concrete blends. Plastic aggregates helped confer greater elastic toughness and a higher thermal resistance to concrete. Plastic aggregates with a high bulk density, such as those derived from PVC, generated concretes with the best mechanical performances. This recycling technique seems promising for heterogeneous plastic streams, particularly when several polymers are present, since its quality parameters differ from conventional thermomechanical recycling.
Martin, Olivier. "Etude de la coextrusion de systèmes biodégradables à base d'amidon de blé plastifié". Reims, 2001. http://www.theses.fr/2001REIMS013.
Pełny tekst źródłaSharkawi, Tahmer. "Étude de facteurs susceptibles d'influencer la biofonctionnalité de nouvelles prothèses endovasculaires temporaires à base de polymère biorésorbable". Montpellier 1, 2007. http://www.theses.fr/2007MON13512.
Pełny tekst źródłaLongieras, Antoine. "Mise au point d'un milieu solide inerte pour l'étude de la biodégradation des polymères dans le compost". Reims, 2005. http://theses.univ-reims.fr/exl-doc/GED00000336.pdf.
Pełny tekst źródłaThe purpose of our research was to set up a vermiculite based inert solid medium which allows us to enhance reproductibility of biodegradation tests in compost, to simulate degradation of materials in compost and to establish carbon balance. In a first step, wheat starch has been used as a model biodegradable polymer and we have shown that degradation of this product in an inert solid medium was similar to the degradation in compost. A carbon balance has been established with a satisfactory accuracy. In a second step, we have applied the method to the degradation of synthetic biodegradable polymer such as PLA of PHB. A carbon extraction protocol based on PLA hydrolysis in NaOH has been proposed and we have followed the evolution of the various terms of the PLA degradation carbon balance, Biomass, carbon dioxide, soluble by-products and remaining polymer. A different protocol has been proposed of PHB based on biomass oxidation but it still needs some improvement. This work constitutes a first approach in polymer inert solid media degradation tests and it highlights the fundamental steps which further work should be focused on
Kedzierski, Mikaël. "Pollutions du milieu littoral par les microplastiques : Méthodes d’évaluation". Electronic Thesis or Diss., Lorient, 2017. http://www.theses.fr/2017LORIS464.
Pełny tekst źródłaPlastics are technical materials necessary for industrialized societies. However, in the early 2000s, plastic particles of about ten microns were observed in seawater samples. These are called "microplastics". Their presence in most environments has been progressively highlighted making it an anthropocene marker. Moreover, these particles interact with environments and may carry toxic additives or micropollutants. However, scientific and technical barriers limit this accurate evaluation. In this context, the aims of this work are (1) to determine the most efficient and cost- effective extraction conditions of microplastics trapped in sand and (2) to evaluate the toxicity due to the interactions between micropollutants and aged plastics, which can occur in the marine environment. Thus, an elutriation system prototype has been built and an adapted protocol developed to efficiently extract microplastics from sand. In order to determine the optimal elutriation flow velocities, a simple numerical model based on hydrodynamic equations has been developed. This numerical model has been validated by comparing theoretical and experimental results. However, these results also demonstrate that process optimization was required: based on different constraints, for example the time needed to achieve the elutriation or the size of the column, new data on the design have been acquired. The evolution of the surface state and the toxicity of 3 types of plastic (PVC, PET and PBAT) immersed in the marine environment during 550 days was studied on Kernevel harbor (Larmor-Plage, France). The results of the plastics ageing show very different behaviors. PBAT ages faster than PVC whereas PET does not exhibit large modifications. The aging of PVC is accompanied by a loss of compounders characterized by an estrogenic activity and by the adsorption of heavy metals. In the marine environment, the degradation of the PBAT surface forms cavities in which clay particles can be trapped. Moreover, in a more punctual manner than PVC, this material exhibit strong estrogenic activities
Amgoune, Abderrahmane. "New group 3 organometallic complexes for ring-opening polymerization of lactones and lactide". Rennes 1, 2006. http://www.theses.fr/2006REN1S036.
Pełny tekst źródłaGuidez, Adeline. "Polymères biodégradables compoundés par extrusion assistée eau : Optimisation du procédé et des propriétés d’usage du matériau". Thesis, Lille 1, 2015. http://www.theses.fr/2015LIL10187.
Pełny tekst źródłaWater-assisted extrusion is a method based on the conventional reactive extrusion. The feature of this method is the introduction of a water injection pump at the compression zone of the extruder machine. This process has already been proven in the nanocomposite formulation, usually based on polyamide (PA) matrix with clay nanofillers. The water acts as exfoliating thus allowing better dispersion of the clay within the matrix. A second role was observed, water would act as a plasticizer during extrusion limiting the material. In this context, water-assisted extrusion was studied using two different profile screw, where the second profile is an optimisation from the first. Polyamide 6 (PA6) was used as material reference in order to select new biodegradable polymers. Two polyesters, poly(butylene succinate) (PBS) and poly(butylene succinate adipate) (PBSA) have shown similar abilities comparared with PA6 extruded under water. After extrusion of the polymers with water injection, a limitation on the decrease in molecular weight was observed. Mechanical and rheological properties of PA6 were improved. Subsequently, an application of this method was conducted on the formulation of a PBS matrix composite based on two types of nanofillers clay in order to improve the mechanical properties of PBS and evaluate the water influence during the extrusion process according to the clay used
Wahl, Aurélie. "Distribution et comportement de débris plastiques dans un sol agricole amendé en compost de déchets ménagers". Electronic Thesis or Diss., Rennes 1, 2022. http://www.theses.fr/2022REN1B031.
Pełny tekst źródłaPlastic waste is accumulating in all environmental compartments, and its presence is of great interest to the scientific community. However, plastic waste study in soils is only very recent compared to rivers and oceans. This PhD work therefore focused on the behaviour of micro- and nanoplastics and associated contaminants from the composting of household waste enriched with plastic debris in agricultural soil. The microplastics collected in soil have an advanced degree of weathering that favours the release of small plastic particles such as nanoplastics. In order to identify them, an extraction/identification method was developed and highlighted for the first time, the presence of nanoplastics containing the three most common polymers in the uppermost soil surface layer. It was then demonstrated that these nanoplastics were present in the mineral layers at depth, whereas the microplastics were only present at ploughing depth. Nanoplastics are therefore mobile in soils and can reach the underlying groundwaters. Finally, the role of plastic waste in the concomitant metal contamination found in soil was investigated. The highest concentrations correspond to metals used as additives in the formulation of plastics, but the plastic role could not be implicated with certainty in soil contamination. However, metals and their isotopic signatures are good candidates for tracing nanoplastics in complex natural matrices
Marin, Paul. "Synthèse et caractérisation de nouveaux amorceurs basés sur des complexes de métaux de transition bivalents : vers la synthèse de polyesters stéréoréguliers par polymérisation par ouverture de cycle". Thesis, Paris 6, 2016. http://www.theses.fr/2016PA066703/document.
Pełny tekst źródłaA large part of the plastic materials produced every year in the world are disposed in landfill, representing a serious menace for the environment. Since several decades, industrial and academic scientists are interested in the synthesis of biodegradable polyesters via the ring opening polymerization of biobased cyclic esters like lactide. Despite a large number of initiators described in the literature, several metals remains not well studied. The goals of this thesis were to synthetize and study the polymerization properties of new iron and cobalt (II) initiators with a trigonal bipyramidal geometry. The different initiators were active at room temperature and polymers with a large variety of tacticity were obtained depending on the steric hindrance of the pro-ligand and the metallic center used, with very good activity and in a controlled manner. Highly isotactic-rich PLA (Pm = 0,86-0,91) were obtained with iron (II) based initiators for the first time. Moreover, cobalt (II) initiators gave isotactic and heterotactic-rich PLA with moderate selectivity, constituting two new cases of stereoselectivity switch. These initiators constitute a good starting point for the development of new productive initiators for the stereoselective polymerization of rac-lactide based on non-toxic and abundant metals and easily accessible pro-ligands
Mangeon, Pastori Carine. "Valorisation des huiles colza / tournesol pour la production de bioplastiques". Thesis, Paris Est, 2018. http://www.theses.fr/2018PESC1002.
Pełny tekst źródłaPoly (3-hydroxyalkanoate)s (PHAs) are an alternative to petroleum-based plastics because of their biodegradability and their biocompatibility. However, the high production costs, the limited mechanical performance and the narrow processing window of PHAs have limited their development on a larger scale. It is therefore necessary to modify the PHAs in order to increase their properties and develop strategies to reduce their production costs to allow their use as replacement for conventional plastics. Among the raw materials derived from renewable resources, metropolitan rapeseed or sunflower oils are interesting candidates for the synthesis and chemical modification of PHAs because of their competitive cost, their bioavailability and their built-in functionalities. Thus, we aimed to reduce the cost productions of PHAs by using rapeseed oil and glycerol as cheap substrates. The strain, Haloferax mediterranei, has demonstrated its ability to biosynthesize a PHB92HV8. In addition, we have developed two approaches to improve the performance of PHAs: plasticization of PHAs by terpene molecules from plants and synthesis of semi-interpenetrating networks (semi-IPNs). The use of terpenes for the formulation of PHAs reduced the processing temperature of the polymer and increased its flexibility. The synthesis of a biobased semi-IPN is obtained by crosslinking sunflower oil and a trifunctional thiol, using the thiolene reaction, within a matrix of linear PHAs. The network improved the thermal stability of PHAs and increased their elongation at break of 2400%. Finally, new biobased materials were also produced from terpenes and vegetable oil, using a simple and "green" process. The resulting materials exhibited flexibility and elasticity with the ability to absorb and to release antibacterial and antifungal hydrophobic molecules such as the eugenol. Therefore, a wide range of bioplastics have been synthesized using vegetable oils, PHAs or a combination of both, with wide range of properties to compete with plastics derived from fossil resources
Belibel, Rima. "Synthèse et caractérisations de nouveaux polyesters biodégradables dérivés du poly (acide 3,3-diméthylmalique) comme revêtement prometteur de stents cardiovasculaires". Thesis, Sorbonne Paris Cité, 2015. http://www.theses.fr/2015USPCD065/document.
Pełny tekst źródłaWith the exception of bibliographic chapter, this thesis was written in the format of collection of articles with abstracts and discussions while comparing the results with other’s in the literature in the same research theme. This work is organized in three tasks: organic synthesis and stereochemistry of polymers, surface physicochemical properties and biological response and degradation study of polymers. The issue of this thesis is based on in-stent restenosis which represents the major complications of angioplasty with stent placement. Drug-eluting stents are currently the solution used for the restenosis treatment. These are metal stents coated with a polymer having a bioactive substance which is generally an antiproliferative agent. The polymer role is to create a protective barrier between the metal and the arterial wall. This barrier must improve the roughness and the chemical composition of the metallic stent, repair the endothelium by the proliferation of endothelial cells and inhibit the proliferation and the migration of smooth muscle cells which are responsible to the reformation of atheroma plaque. The surface properties confer to polymer a strong adhesiveness to the metal and biocompatibility vis-a-vis of the arterial wall. Interaction created between the polymer coating and vascular cells are modulated by the physicochemical properties of the surface. It is in this context that my thesis is organized into two themes.The first aim of my thesis is to develop a series of amorphous polymers and study their physicochemical (wettability, roughness ...) and biological properties (adhesion, cell behavior and proliferation) and then correlate these properties to choose the promising coating coronary stent. A degradation study was also conducted on elaborate systems. The second is dedicated to chemical synthesis and stereochemistry of polymers. Indeed, new optically active monomers and the corresponding stereopolyesters were synthesized and characterized in order to compare their physicochemical properties with those of amorphous polyesters studied as a coating of the stent and enhance the biomaterials field
Oudoua, Kaouthar. "Elaboration de microcapsules (bio)dégradables". Electronic Thesis or Diss., Aix-Marseille, 2022. http://www.theses.fr/2022AIXM0252.
Pełny tekst źródłaMicroencapsulation is a process that protects a hydrophobic substance in a capsule whose size can vary between 1 and 100 micrometers. The core of the capsule is thus isolated from its external environment. This allows to delay its evaporation, its release or its deterioration. This technology is mainly used in the fields of hygiene and home products. The main technology used to create the wall of these capsules is based on the reaction between melamine and formaldehyde which produces a cross-linked thermoset (MF) at the oil/water interface. Recently, environmental concerns about non-degradable microplastic waste have become a global issue. MF microcapsules with non-degradable walls and based on reagents that may pose toxicity concerns contribute to this problem. The aim of this thesis is to develop a new type of microcapsule, easy to synthesize, without using expensive and toxic raw materials, which is (bio)degradable in natural environment, which can be used with a large number of active ingredients, and which provides a good protection to the active ingredient it is intended to protect. During this thesis, we were able to develop a new generation of (bio)degradable microcapsules by developing the interfacial polymerization of poly(β-aminoester). This polymer has already been successfully used in several biomedical applications due to its very good biocompatibility and biodegradability. We have explored and introduced new applications for these non-toxic and biodegradable poly(β-aminoester) microcapsules, especially in the detergent field
Durance, Loïc. "Développement d'une méthode de stérilisation par la chaleur de solutions injectables conditionnées en polyéthylène basse densité". Amiens, 2003. http://www.theses.fr/2003AMIED003.
Pełny tekst źródłaThe solutions for injection are usually packaged in glass flasks and sterilised by moist steam. Is the current tendency to substitute glass by the plastic because it reduce the obstruction of conditioning while increasing its shock-proofness and allows a board elimination of the wastes by incineration. Only some plastics meet both public health regulations and ecological requirements. Among them, low density polyethylene (LDPE) offers various advantages. It possesses virtually no additive, which limits the interaction hazards between plastic and chemical substances used in injection preparations. Its destruction does not bring chlorine-containing waste or other toxic matter into the atmosphere. Moreover, it is fully adapted to the various manufacturing technologies for large-scale production as the blow-fill-an-seal. However, the temperature value admitted for sterilisation is 121°C, whereas LDPE exhibits a melting point at about 117°C. Therfore, we have developped an alternative cycle of sterilisation based on F0 concept at a temperature lower than 121°C and such as it respected the LDPE containers integrity. The efficiency on the micro-organisms destruction have been calculated aid of stocks spores of Bacillus Stearothermophilus introduced into the recipients which contained water for injection as base solution. The sterilised products have been followed throughout this period. The information obtained by this work have the aim of documenting a manufacturing authorization file about products for injection for its recording with the benefit of a pharmaceutical industry of Amiens
Frère, Laura. "Les microplastiques : une menace en rade de Brest ?" Electronic Thesis or Diss., Brest, 2017. http://www.theses.fr/2017BRES0046.
Pełny tekst źródłaWorld production of plastics has increased steadily for the past decades leading to a major contamination of the worldwide aquatic ecosystems recently estimated at more than five trillion plastic pieces floating the surface of the oceans. Microplastics (plastic particles < 5 mm) are introduced into aquatic environments directly as industrial raw material (plastic pellets, cosmetics, clothing) or indirectly via the fragmentation of larger plastics. This emerging contaminant represents an increasing ecological concern for science and society. The present study focused on the microplastic contamination of the Bay of Brest (Brittany, France), a macrotidal coastal ecosystem characterized by intense anthropogenic activity. The main objectives were: (1) to evaluate the contamination of environmental matrices (surface water, subtidal sediment and biota) by microplastics, and (2) to identify their potential role as vector of chemicals and bacteria in the bay of Brest.Methodological developments were first conducted to improve microplastic extraction from environmental matrices as well as their rapid morphological and chemical identification by Raman micro-spectrometry. The field investigations showed that the ecosystem of the bay of Brest is contaminated by microplastics with mean concentrations of 0.24 ± 0.35, and 0.97 ± 2.08 (mean ± standard deviation) in surface water and sediment, respectively. Microplastic contamination in surface water and sediment was dominated by polyethylene, polypropylene and polystyrene microparticles.Spatial microplastic distribution appeared to be related to proximity to urbanized areas and to hydrodynamic in the bay. Preliminarily results of microplastic contamination in marine bivalves demonstrated relatively low contamination (0.01 ± 0.04, and 0.08 ± 0.34 for mussels and cockles, respectively) by microplastics (mainly polyethylene and polypropylene fragments), however this could be partly related to the methodological limitation identified here (e.g. exclusion of fibers). Organic pollutant (PAH, PCB and pesticides) were detected on floating microplastics at levels (not detected – 49,763 ng g-1, mean ± SD) similar to those measured in sediment and bivalves suggesting low risks in transferring hazardous chemicals in local marine organisms upon microplastic ingestion. Finally, distinct bacterial community assemblages were demonstrated on microplastics as compared with surrounding surface water; the Vibrio genus was identified as a discriminant biomarker of the plastic matrix. Overall, this work provides a first and thorough assessment of the microplastic contamination in the bay of Brest and solid methodological recommendations for further work
Basiak, Ewelina. "Study of the chemical, physical and functional properties of edible starch-based films". Thesis, Dijon, 2016. http://www.theses.fr/2016DIJOS018/document.
Pełny tekst źródłaThe amount of waste increased annually, mainly from plastic industry. Plastic materials were more produced during the only last ten years than during the last millennium. A potential solution of the ecological and economic problems can be biodegradable or edible films and coatings. The goal of this thesis was to study edible films and coatings based on starch. Fifteen types of film-forming solutions were made: 3 types of starch, starch + different amounts of plasticizer, starch + proteins, starch + oil. To better understanding the interaction between film components, physical, chemical and functional tests were done. Finnaly, validation on real foods (plums) as coatings and films helped to improved edible barrier films for fruit and vegetable preservation.Preliminary physico-chemical studies of corn, potato and wheat starch film properties allowed choosing the wheat starch-based films further experiments. Then, a 50% amount of plasticizer related to dry biopolymer weight was selected aiming to obtain films being not too rigid, that did not break and without blooming. To prove the barrier moisture efficacy, rapeseed oil was added as multilayers films. Microstructure observations displayed that oil was dispersed as droplets instead of layer, thus emulsion-based films were obtained instead of multilayer starch-oil-starch films. Various ratios of starch/protein were assessed to improve functional properties of films. The more the protein content was, the better the barrier efficiency against water vapour, oxygen or aroma were. Indeed, higher protein content films were more dense and homogeneous. From these data obtained on films, and the better understanding how composition and structure affect film performances, several recipes were tested as coatings or films for wrapping fresh plums. Thermographic analysis was used to study the plums behavior during storage, and starch coating was efficient to delay fruit degradation
Z każdym rokiem wzrasta liczba produkowanych odpadów, w szczególmości tych z plastiku. W ciągu pierwszych dziesięciu lat wyprodukowano więcej tworzyw sztucznych niż w przeciągu całego ubiegłego tysiąclecia. Rozwiązaniem tych ekologicznych i ekonomicznych problemów mogą okazać się filmy i powłoki do żywności. Celem tej pracy były studia nad jadalnymi filmami i powłokami na bazie skrobi. Piętnaście rodzajów roztworów powłokotwórczych zostało wytworzonych: z 3 typów skrobi, skrobia + różne stężenia plastyfikatora, skrobia + białka, skrobia + olej. W celu lepszego zrozumienia interakcji pomiędzy komponentami filmu właściwości fizyczne, chemiczne i funkcjonalne zostały zmierzone. W ostatnim etapie walidacja na prawdziwej żywności (powlekanie i pakowanie śliwek) pomogła w udowodnieniu istnienia właściwości barierowych owoców i warzyw podczas przechowywania.Próbne testy fizyko-chemiczne skrobi kukurydzianej, ziemniaczanej i pszenicznej pomogły w wyborze skrobi otrzymywanej z pszenicy do dalszych badań. Następnie wybrano zawartość plastyfikatora. 50% glicerolu względem suchej masy substancji powłokotwórczej nie powodowało twardości i pękania filmów ani też tzw. efektu kwitnienia (intensywnie żółty/ pomarańczowy kolor filmów). W celu poprawy właściwości barierowych olej rzepakowy został dodany. Zdjęcia mikroskopowe obrazują zawieszone krople oleju w matrycy jako emulsja zamiast dodatkowej warstwy, której oczekiwano. Do skrobi zostały dodane również białka serwatkowe w kilku proporcjach. Im więcej białek jest w stosunku procentowym skrobia/proteiny tyym lepsze są właściwości barierowe dla pary wodnej, tlenu i aromatów. Dodatkowo filmy zawierające więcej protein w stosunku procentowym są bardziej gęste i jednolite. Uzyskane informacje pozwoliły na lepsze zrozumienie wpływu kompozycji i struktury filmów i powłok na pakowanie świeżych śliwek. Analiza z użyciem kamery termowizyjnej pozwoliła na ocenę zmian w owocach podczas przechowywania, zaś powłoka skrobiowa efektywnie opóźniała procesy degradacyjne w owocach
Abdillahi, Houssein. "Propriétes barrière et mécaniques d'agromatériaux thermoplastiques à base de farine de blé et de polyesters biosources et biodégradables". Thesis, Toulouse, INPT, 2014. http://www.theses.fr/2014INPT0027.
Pełny tekst źródłaFrom basic and essential to unnecessary and optional consumer products, packaging, particularly plastic, is today an indispensable part of our daily life. Its extensive use in the food industry for a single use and for a short shelf-life encourages us today to move towards new renewable and biodegradable materials with similar characteristics than their counterparts from fossil resources. Biopolymers and biopolyesters blends can be a good alternative. Within the framework of this present work, wheat flour, thermoplasticised by glycerol and water, and biobased and biodegradable polyesters such as PLA and/or PHB, were blended using an industrial twin screw extruder and were injection-molded into thermoplastic materials. Thermal, dynamic thermomechanical, morphological, mechanical and barriers properties of these new materials were studied. Citric acid was used as a compatibilizer to improve the interface starch/PLA. The different investigations have allowed us to develop various types of formulations, with mechanical characteristics and barrier properties to water vapor, very attractive for manufacturing plastic food packaging which can be used for meats or cheeses. Food contact suitability and biodegradability of thermoplasticised wheat flour/polyester materials have also studied
Julien, Jean Mario. "Développement de polymères et composites alvéolaires bio-sourcés à base de poly(acide lactique)". Phd thesis, Lille 1, 2011. http://tel.archives-ouvertes.fr/tel-00726158.
Pełny tekst źródłaMonsaingeon, Baptiste. "Le déchet durable : éléments pour une socio-anthropologie du déchet ménager". Thesis, Paris 1, 2014. http://www.theses.fr/2014PA010654/document.
Pełny tekst źródłaOver the past forty years, household waste and its management have been assimilated to a global environmental issue. While sustainable development is becoming a pressing issue, the number of our garbage bins is increasing. So what is it that we aim to preserve when we are dutifully sorting out our garbage? Between the very local gesture of discarding and the global environmental issue, there is a tremendous gap. The link between everyday practices of waste and environmental issues is so underdetermined that it has to be analysed. The main claim of this dissertation is that despite a growing concern with environment and the increasing time and space devoted to waste management, we remain unaware of the social, technological and material issues at stake. Because of this individual and collective blindness waste is not seen as a clue: as its memorial function is neglected waste is still perceived as what has to disappear, as a material quantity that has to be controlled and eliminated. The en-durable waste is an oxymoron that leads to further investigate the multiple modes of presence of waste in today’s life. Inspired by the personae of the ragman and of the archaeologist, this socio-anthropological investigation follows household waste from uncertain oceans of plastic to few Parisian vermicompost bins. Based on this confrontation to the materiality of waste, to the territories and to practices of wasting, this dissertation claims that where the unavoidable presence of waste is described as a problem, it is question of our presence to waste that is at stake
Julienne, Fanon. "Fragmentation des plastiques : effet de l’environnement et de la nature du polymère sur la taille et la forme des fragments générés". Thesis, Le Mans, 2019. http://www.theses.fr/2019LEMA1033.
Pełny tekst źródłaPlastic wastes have been accumulating for several decades in the oceans where they break up into particles called microplastics when their size is less than 5 mm. These microplastics are found in all earth’s waters, in sediments and in many marine organisms. Their long-term physico-chemical fate and their possible fragmentation into nanoplastics are complex, still poorly documented and require laboratory studies.In order to understand the processes related to photodegradation and fragmentation of polymers, but also in order to understand the evolution of these fragments during irradiation, an accelerated aging protocol in abiotic conditions has been set up. The oxidation and fragmentation of two model polymers, low density polyethylene and polypropylene, were monitored using spectroscopic techniques (InfraRed, Raman), DSC, contact angles and microscopic technics (light microscopy, polarized light, SEM, AFM ...).This work has demonstrated a significant influence of the environment and the initial morphology of the polymers on their kinetics of aging and cracking mechanisms. This lead to significantly different distributions in numbers, sizes and shapes of the generated fragments. Moreover, after a long time of irradiaiton, other degradation products could be detected but the significant production of nanoplastics has not been demonstrated. The possibility of a size limit below which the fragmentation rate of plastics would strongly decrease should be considered
Goument, Caroline. "Caractérisation, mise en forme et recyclage de polymères biosourcés pour le développement d’un procédé de fabrication plastronique respectueux de l’environnement". Electronic Thesis or Diss., Lyon, INSA, 2023. http://www.theses.fr/2023ISAL0109.
Pełny tekst źródłaIn the majority of cases, electronic objects in our everyday life have a plastic casing made of petrochemical polymer materials. Today, replacing the petrochemical-based materials with more environmentally-friendly ones is a necessary transition. 3D plastronics is an emerging field of research than can overcome some of the limitations of conventional electronics, particularly as it requires to redefine the polymer substrates. This PhD is part of the BIOANTENNA project of the AURA Region's Ambition Research Pack, whose goal is to manufacture an innovative electronic device in terms of the materials used and the functionalities of the electronic circuit. In this thesis, we study a mass production process for electronic devices called In-Mold Electronics (IME). It comprises three main stages: screen printing, thermoforming and injection molding. In the state of the art, the reference polymer in IME is PolyCarbonate (PC). Our goal is to replace PC with a more environmentally-friendly material: Poly(Lactic Acid) (PLA). Over the last ten years, this polymer has been the subject of numerous studies in order to use it as an alternative to petrochemical-based engineering polymers. PLA is the most widely used biosourced polymer today. It is also biodegradable in industrial composting, which could provide a solution for end-of-life products and make it suitable for use in the circular economy. This manuscript is divided in two main parts : one regarding the manufacturing of a plastronic device using IME and PLA, and the other on the dismantling of the IME devices manufactured in the first part
Samuel, Cédric. "Apport de la farine de maïs plastifiée dans les mélanges à matrice polyester pour des applications films". Thesis, Saint-Etienne, 2011. http://www.theses.fr/2011STET4019/document.
Pełny tekst źródłaThin compostable films for extrusion blowing, thermoforming and biaxial stretching are in the scope of these works. Blend of thermoplastic flour and compostable polyesters are proposed and studied. Corn flour can be processed in a twin-screw extruder with glycerol in a similar way than starch. Thermoplastic flour shows some differences with starch but still cannot be used in thin film applications. Thermoplastic flour was blended in a melt state with a compostable polyester matrix, PBAT. Matrix / particle morphologies were achieved and linked with individual rheological behaviour. Good global mechanical properties results from these morphologies were discussed in terms of microstructures, dispersed phase deformation under stress and interface properties. Model particles blends with PBAT and microscopical investigations confirmed the mechanical behavior of the dispersed phase. These blends still suffer from inherent problems concerning thermoplastic flour and uncompatibilized blends. A suitable chemistry was developed to overcome these defects based on monomer polymerization from starch. Ring opening polymerization of trimethylene carbonate in presence of hydroxyl functions and organic catalyst or organometallic initiators displays interesting reaction rates for a reactive extrusion process. Model co-initiators with chemical and sterical environments close to starch were used and transposed. Thermoplastic flour modification by polycarbonate grafting was achieved in a reactive extrusion process coupled with his blending in a melt state with PBAT matrix. Compatibilization effects were discussed in terms of microstructures, interface reactions and matrix modifications. Interface modifications were evidenced on mechanical properties of these blends
Deleage, Fanny. "Formulations et modifications par extrusion réactive d'un mélange de polymères biodégradable et partiellement biosourcé". Thesis, Lyon, 2016. http://www.theses.fr/2016LYSES030.
Pełny tekst źródłaBiodegradable plastics need to be more and more competitive. This work, conducted between IMP@UJM laboratory and LCI company had the main objective of increasing the content of renewable materials in the biodegradable blend of poly(butylene adipate-co-terephthalate) (PBAT)/ thermoplastic flour (TPF), without decreasing its mechanical properties. The blend was obtained by a single step extrusion, including flour thermoplastification and blending with the polyester. The scientific challenge was to understand the relationship between processing parameters, the morphology establishment, the concentration of each phase of the blend and its mechanical properties. Then, these results were exploited in order to increase the mechanical properties of the mixture. The influence of the concentration of TPF and the viscosity ratio between the phases was highlighted over the entire concentration range. This highlighted the importance of controlling the interfacial tension of the blend. Mechanisms of the morphology establishment were proposed, as well as interpretations about its effect on the mechanical properties of the blend. Then, a study of the PBAT modification by reactive extrusion was proposed. The evolution of the polyester structure was characterized by size exclusion chromatography, according to various parameters including the mixing time. Finally, various modifications of PBAT/TPF mixture were tested. Modifying the PBAT, the TPF phase or the interface via the compatibilizers were studied in order to tailor the rheological, morphological and mechanical properties