Teses / dissertações sobre o tema "Polyesters biosourcés et biodégradables"
Crie uma referência precisa em APA, MLA, Chicago, Harvard, e outros estilos
Veja os 21 melhores trabalhos (teses / dissertações) para estudos sobre o assunto "Polyesters biosourcés et biodégradables".
Ao lado de cada fonte na lista de referências, há um botão "Adicionar à bibliografia". Clique e geraremos automaticamente a citação bibliográfica do trabalho escolhido no estilo de citação de que você precisa: APA, MLA, Harvard, Chicago, Vancouver, etc.
Você também pode baixar o texto completo da publicação científica em formato .pdf e ler o resumo do trabalho online se estiver presente nos metadados.
Veja as teses / dissertações das mais diversas áreas científicas e compile uma bibliografia correta.
Theron, Benjamin. "Nouveaux catalyseurs pour la synthèse par polymérisation par ouverture de cycle de polyesters biosourcés et biodégradables". Electronic Thesis or Diss., Bourgogne Franche-Comté, 2024. http://www.theses.fr/2024UBFCK002.
Texto completo da fonteResearch on catalysts for the synthesis of bio based and biodegradable (co)polymers has led to the emergence of new families of catalysts (salens, guanidines, phenoxy imines...) and a better understanding of their behavior. The work presented in this manuscript focuses on using new π-donors phenoxy amidines (FA) and biguanides complexes for the ROP of biobased and biodegradable polyesters.The implementation of this theme at the Dijon site, along with highlighting the unique and specific behavior of these new complexes, is presented in this manuscript.Initially, the synthesis of new FA and analogous phenoxy-imines complexes was carried out. Some of these complexes have been shown to produce polylactic acid (PLA) using industrial-grade monomers contaminated with significant quantities of lactic acid. A comparative study conducted with the parent phe-noxy-imine (FI) complexes, showed that they do not work under these degraded conditions. Zinc complexes with bis(phenoxy-amidine) ligands (FAlen) showed the highest activity in ROP of lactide, whereas their salen analogs do not catalyze this polymerization reaction.Tests were conducted on lactide and butyrolactone ROP using new mono- and bimetallic zinc and aluminum biguanide catalysts. The zinc biguanide catalyst produced the highest lactide ROP activity ever reported for a monometallic system
Hallavant, Kylian. "Etude de la mobilité moléculaire de polyesters biosourcés à structures chimiques contrôlées". Electronic Thesis or Diss., Normandie, 2024. http://www.theses.fr/2024NORMR041.
Texto completo da fonteThe decline of fossil resources and the raise of collective awareness about the impact of plastic waste on the environment impose to look for possible alternatives to petroleum-based polymers with reduced carbon footprint and environmental risks. For this reason, bio-sourced and/or biodegradable polyesters have attracted much attention from both academic researchers and industrials. This thesis focuses on the thermal characterization of co-polyesters based on hydroxy-fatty acids, which are extracted from tomato-peel agro-wastes, and poly (alkylene trans-1,4-cyclohexanedicarboxylate) (PCHs), which are biodegradable and potentially biobased materials with interesting barrier properties. This thesis shows that both systems have high crystallization rates and form complex microstructures involving several polymorphs with a high density of small spherulites. The microstructure depends on the processing conditions (cooling rate from the melt, crystallization temperature) and on the chemical nature of the material (crosslinking density for the hydroxy-fatty acids, and alkyl chain length within the main structure of the repeating unit for the PCHs). Crosslinking reduces the mobility of the macromolecular chains and inhibits crystallization, whereas the alkyl chain length induces an odd-even effect with consequences on the melting and crystallization temperatures, on the coupling between the amorphous and crystalline phases, on the fragility index and on the glass-forming ability
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.
Texto completo da fonteFrom 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
Freyermouth, Floriane. "Etude et modification des propriétés du poly(butylène succinate), un polyester biosourcé et biodégradable". Thesis, Lyon, INSA, 2014. http://www.theses.fr/2014ISAL0009/document.
Texto completo da fonteWithin the frame of sustainable development, biobased and biodegradable polymers are going to play an important role according to economic and environmental perspectives. The polyolefins currently used in packaging and automotive industries will be replaced by biomaterials. The poly(butylene succinate), an “old” aliphatic polyester, has recently regained interest thanks to its biobased and biodegradable potential and mechanical properties similar to polyolefins. However, this polyester is very sensitive to degradation even at mild ambient conditions and, even though its flexibility is comparable to polyethylene or polypropylene, its modulus is too low. Some modifications of the chemical structure were considered to improve the long-term use of PBS. The synthesis of random copolymers using long-chain fatty acid Pripol 1009 or terephthalic acid allows to reduce significantly the hydrolysis rate and properties are maintained during a longer time. The incorporation of fillers like calcium carbonate and talc also enhance the PBS stability. The addition of calcium carbonate neutralizes carboxyl terminal group, which play an autocatalytic role in the hydrolytic degradation. High aspect ratio of talc increases the gas and liquid diffusion path, reducing permeability and providing better barrier properties to the material. In order to improve Young’s modulus, formulating blends with mineral fillers like calcium carbonate and talc, or with more rigid polyesters like polylactic acid or poly(butylene terephthalate) are efficient. The most interesting results are obtained by using calcium carbonate and polylactic acid, which allow the preservation of PBS’s flexibility. Processing parameters should be maximized to limit the degradation of PBS. Combinations of the most interesting solutions were investigated and lead to materials which fulfill the required specifications
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.
Texto completo da fonteBiodegradable 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
Vandesteen, Marie. "Synthèse et modification d'un polyester biodégradable pour application agro-textile : le poly(butylène succinate)". Thesis, Lyon, INSA, 2015. http://www.theses.fr/2015ISAL0022.
Texto completo da fonteIn the last decade, biodegradable polymers have gained significant interest for agricultural applications. Here we focus on the development of biodegradable textiles for insect-proof nets. Currently these textiles must be collected by specialized companies after the growing season and generate disposal cost. An ideal agrotextile would be collected by the user at the end of the growing season, and undergo full mineralization within few months. These requirements can be achieved by using biodegradable polymers. In this study, poly(butylene succinate) (PBS), a biobased and biodegradable polymer was studied. PBS was synthesized by polycondensation on a pilot plant reactor. Because of low rheological properties of the synthesized polyester, the chemical structure of PBS was modified by several approaches like chain extension or branching. The mechanical properties were tuned with the synthesis of PBS/PLA transreacted systems and PBS nanocomposites. These modified PBS were tested upon fiber spinning. Finally a PBS yarn with 0,5% spherical silica was produced at higher scale and a textile was done. Ageing of the PBS yarns was also studied and the conservation of the mechanical properties during use of the textile was validated. Lastly a more exploratory approach was tested. It is synthesis of modified PBS by supramolecular interactions, which are reversible upon temperature
Maafi, El Miloud. "Nouveaux matériaux polymères biodégradables: élaboration et étude des propriétés". Reims, 2010. http://www.theses.fr/2010REIMS029.
Texto completo da fonteThis work consists in developing new potentiallly biodegradable materials ans studying their thermal and mechanical properties. In the first part, we synthesized new polymers of type polyesters and polyurethanes by polycondensation of telechelic polycaprolactone oligomers with other monomers chosen according to some physical properties and degradability of the materials obtained. The analyses show that the thermal and mechanical properties of these polylmers are influenced by the method of synthesis anfd the percentage of terephthalic untils uncorporated into these polymers. The second part has been dedicated to the development of the composites based polyurethanes synthesized from castor oil or PCL and biopolymer: cellulose. The later has been extracted of the alfa plant, very abundant in plant biomass Moroccan. The study of properties of these materials shows that the cellulose fibers significantly improve the thermal and mechanical properties of composites. This improvement varies linearly with the rate of fiber incorporated to a certain percentage. Beyond this value the mechanical properties fall. The SEM images of fracture surfce of composites show a good interface due to hydrogen bonding between the fibers and matrix
Nottelet, Benjamin. "Synthèse et caractérisation de nouveaux polyesters biodégradables et hydrosolubles à fonctions cationiques ou amphotères". Montpellier 2, 2005. http://www.theses.fr/2005MON20129.
Texto completo da fonteBonduelle, Colin. "Hétérocycles oxygénés : Synthèse, Réactivité et Application à la préparation de polymères Biodégradables". Phd thesis, Université Paul Sabatier - Toulouse III, 2008. http://tel.archives-ouvertes.fr/tel-00390646.
Texto completo da fonteL'utilisation des lactones est parfois limitée à cause de leur faible polymérisabilité. Cette dernière est contournée par l'utilisation de systèmes catalytiques très réactifs souvent à base de métaux qui ne sont pas toujours compatibles avec une application en biologie (pharmacologie, environnement)2. Une approche pour pallier ce problème consiste à activer ‘chimiquement' ces monomères pour en tirer un avantage dans le processus de polymérisation. Le L-lacOCA est ainsi un analogue du L-lactide qui possède une fonction O-carboxyanhydride (OCA). Ce monomère est beaucoup plus réactif que la dilactone cyclique équivalente : il polymérise de façon contrôlée et vivante dans des conditions catalytiques plus douces3.
Ce travail commence par une étude théorique de la ROP du L-lacOCA et du L-lactide catalysée par la 4-diméthylaminopyridine (DMAP) et en présence d'un alcool. Le mécanisme de la polymérisation ainsi révélé consiste en une activation basique de l'amorceur par la DMAP. Pour ce catalyseur, il y a mise en évidence pour la première fois d'un mode d'action bifonctionnel inusuel qui met en jeu une liaison hydrogène de faible énergie4.
La deuxième partie du manuscrit décrit le développement de la ROP du L-lacOCA avec un systême catalytique alternatif écocompatible : la catalyse enzymatique. Jusqu'à maintenant, les enzymes réalisent difficilement la ROP du lactide. Avec deux lipases, la Novozyme 435 et la lipase PS, il a été possible d'obtenir du polylactide de haut poids moléculaire à partir du monomère activé. Dans le cas de la Novozyme 435, la polymérisation est contrôlée et possède un caractère vivant.
Dans une dernière partie, nous avons essayé d'étendre le principe d'activation du motif OCA à d'autres monomères. Nous avons étudié la ROP des β-OCAs, les O-carboxyanhydrides à 6 chaînons qui pourraient donner accès aux polymères naturels comme le PHB. Trois monomères de ce type, le PivOCA, le MepOCA et le ButOCA ont été synthétisés. L'étude de leurs réactivités a mis en avant un problème de sélectivité entre les deux carbonyls du motif OCA lors d'une attaque nucléophile. A cause de réactions secondaires, les essais de ROP ont montré qu'il était difficile d'accéder proprement à des polyesters.
Références
1. Biopolymers, Wiley VCH, 2003, Vol. 3a-3b-4.
2. O. Dechy-Cabaret, B. Martin-Vaca, D. Bourissou, Chem. Rev., 2004 (104) 6147.
3. O. Thillaye du Boullay, E. Marchal, B. Martin-Vaca, F. P. Cossio and D. Bourissou., J. Am. Chem. Soc., 2006 (128) 16442.
4. C. Bonduelle, B. Martin-Vaca, F.P. Cossio, D. Bourissou, Chem. Eur. J., 2008 , 14, 5304.
Mortain, Ludovic. "Elaboration et étude de nouveaux matériaux biodégradables à partir de bois et de poly(epsilon-caprolactone), vecteurs de principes actifs". Caen, 2004. http://www.theses.fr/2004CAEN2006.
Texto completo da fonteBelibel, 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.
Texto completo da fonteWith 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
Goujard, Laurent. "Synthèse de polyesters biodégradables par des lipases produites par des micro-organismes lipolytiques, isolés de feuilles à cuticule épaisse, et par une lipase immobilisée, le novozym 435". Aix-Marseille 3, 2009. http://www.theses.fr/2009AIX30046.
Texto completo da fonteThe aim of this thesis has been the enzymatic synthesis of biodegradable polyesters from renewable resources issued from oleaginous plants: glycerol and di-oleic acid. To work out the economical problem, due to the cost of the most efficacious bio-catalyser for polyesterification, the immobilised lipase of Candida antarctica B (Novozym 435), new microbial lipases has been researched in litters of Mediterranean plant species. With this object, a new methodology has been developed allowing to measure the potentialities of lipolytic enzymes to synthesise polyesters. These enzymes has been produced by micro-organisms able to degrade a natural polyester, the cutin. A thermophilic bacterium (BT2) has been selected among the isolated strains. Their capabilities to catalyse polyesterifications has been evaluated and compared to those of Novozym 435. This last bio-catalyser has also been used to study an apparatus to synthesise polyesters in bulk. In this conditions, an elastomer product was obtained with a molecular weight higher than 134 kDa. Biodegradability measures have shown that this polyester is faster mineralised than polyesters produced by heating from 160°C up to 180°C. The impact, of the a[w], molar ratio glycerol/acid and enzyme quantity in the reacting medium, on the yield and on the molecular weight of the polyesters formed has been studied
Hegde, Vikas. "Etudes diélectriques des matériaux biodégradables et/ou bio-sourcés". Thesis, Université Grenoble Alpes (ComUE), 2017. http://www.theses.fr/2017GREAT031/document.
Texto completo da fonteThe declining resources of fossil fuels, increase in wide-spread pollution, emission of green-house gases and difficulties in recycling waste materials are pushing biodegradable polymers into prominence. In the domain of electrical engineering, many polymers find applications in various electrical insulation systems. These polymers are petro-based, not eco-friendly and most of them are not biodegradable. With an objective to replace conventional products, biodegradable polymers are explored for their dielectric properties.In this work, a detailed study on the present status in the research work on biodegradable polymers in the electrical engineering domain is presented. Thermal and electrical properties of both biodegradable and classical polymers are compiled and compared.The polymers processed and studied were Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), Polycaprolactone (PCL), Poly(lactic acid) (PLA) and PLA based nanocomposite. Dielectric properties for a wide range of temperature and frequency were measured by dielectric spectroscopy and analyzed with the help of DSC and DMA experiments. Volume resistivity and electrical breakdown were measured on few polymers. These biodegradable polyesters were compared with conventional polymers
Dessauw, Etienne. "Etude et développement de structures fibreuses non-tissées résistantes à la pénétration bactérienne". Thesis, Paris Est, 2019. http://www.theses.fr/2019PESC0014/document.
Texto completo da fonteThe purpose of this work is to develop new antibacterial non-woven porous structures. Different strategies were developed: one was to develop porous structures by electrospinning using a biosourced and biocompatible polymer, the other was to modify a fibrous support from a commercial respiratory protection mask. Assembling materials using ionic interactions by alternatively superposing cationic polymer layers and anionic polymers on the surface of the polypropylene (PP) median filter allowed to develop new structures with good antioxidant and antibacterial properties. The anionic polymer, derived from the cyclodextrin polymer, has the advantage of being able to encapsulate a bio-based antimicrobial agent, carvacrol. Another approach was to modify PP filters with tannic acid, a naturally occurring polyphenol. In this study, two strategies were implemented to functionalize PP with tannic acid (TA). The first is the reactive extrusion of PP with TA in the presence (or not) of dicumyl peroxide (DCP) to directly graft tannic acid onto PP. The second strategy consists in polymerizing the TA through a porous layer of PP extracted from a commercial mask, in order to allow the physical immobilization of the TA on the surface of the PP fibrous mat. Surface grafting using a "grafting from" process was also studied. These materials have shown good anti-free radical properties
Robert, Carine. "Synthèse Tandem de Polyesters alternés à partir de Ressources Renouvelables". Phd thesis, Université Pierre et Marie Curie - Paris VI, 2012. http://pastel.archives-ouvertes.fr/pastel-00830370.
Texto completo da fonteGarg, Garima. "Solvants ioniques biosourcés et CO2 supercritique : conception des processus durables pour la synthèse de molécules cibles (BISCO2)". Thesis, Toulouse, INPT, 2019. http://www.theses.fr/2019INPT0085.
Texto completo da fonteThis Thesis represents a multi-disciplinary project where aspects going from solvent engineering to catalysis using metal-based nanoparticles, are explored. In this project, solvent engineering has been applied to bio-based deep eutectic solvents (DES) synthesized from choline tosylalaninate and glycerol in an effort to decrease the solvent viscosity by using different amounts of carbon dioxide. In this context, molecular rotors were used as an innovative method to measure the viscosity, avoiding the use of expensive instrumentation and giving the possibility to access to the microviscosity of the system. Furthermore, DES have been applied for the synthesis of palladium nanoparticles, also acting as stabilizers, which were fully characterized. The as-prepared palladium nanoparticles were then used for catalytic hydrogenations of unsaturated C-C bonds, and nitro and carbonyl groups. Sub and supercritical CO2 conditions have been applied to improve the efficiency of the palladium nanocatalysts in hydrogenation reactions and afterwards for the extraction of organic products. This work represents an effort to intensify a hydrogenation process in a highly viscous, non-volatile, biodegradable, and non-toxic DES by using CO2 in order to decrease mass transfer limitations and to extract products from the reaction media
Thongkham, Somprasong. "Synthèse de lactones fonctionnalisées par réaction de thiol-ène et leur application à la préparation de polymères biodégradables de propriétés modulables". Thesis, Toulouse 3, 2019. http://www.theses.fr/2019TOU30295.
Texto completo da fonteThe development of new sustainable polymers endowed with improved performances but minimal environmental impact has become a major concern. In this context, aliphatic polyesters are attracting increasing attention in the medical field and packaging applications, due to their biodegradable character and suitable physical properties. Ring-opening polymerization (ROP) is a method that has been used in these areas to access a broad range of polyesters with different and well-controlled structures. One of the well-known lactone monomers for ROP is epsilon-caprolactone (epsilon-CL), a compound derived from petrochemical source. An alternative lactone monomer derived from biomass is epsilon-decalactone (epsilon-DL). Being a 7-membered ring as epsilon-CL, epsilon-DL is thus a renewable monomer that is attracting increasing attention. However, the pendant butyl group at epsilon-position has a large impact on mechanical and thermal properties as well as degradation rates. To modulate these properties, we have been working with the functionalized monomers of close structure to ensure similar behavior in ROP. First, the epsilon-functionalized-epsilon-CL monomers were prepared from 6-heptynoic acid by a sequential transition metal catalyzed cycloisomerization and subsequent thiol-ene reaction. Afterwards, their copolymerization with epsilon-DL has been explored including the identification of controlled/living polymerization using InCl3-based bicomponent catalyst and the confirmation of their random architecture. In addition, the preparation of copolymers featuring pendant carboxyl groups by post-modification steps have also been completely achieved. Finally, the hydrolytic and enzymatic degradation of these functionalized copolymers has been thoroughly investigated, proving the influence of our new functionalized monomer (in deprotected form) on degradation rates of PDL
Chabert, Adèle. "Traitement biosourcé du Hêtre par la formation in situ de polyesters à base d’Acide Malique - Étude du procédé et des propriétés physiques conférées, du petit échantillon à l’échelle de la planche". Electronic Thesis or Diss., Université de Lorraine, 2022. http://www.theses.fr/2022LORR0252.
Texto completo da fonteWood is a hygroscopic material whose dimensions will vary with the hygrothermal conditions of the surrounding environment. One of the wood species the most susceptible to dimensions variations in France is beech wood. It is very abundant in Europe, and has a low durability, requiring additional protection to improve it and extend its use. This thesis work studied several bio-based treatments by the in situ formation of malic acid-based polyesters. Two types of alcohols were used, one is ramified, the glycerol, and the other one is linear, the 1,4-butanediol, to observe if a lower crosslinking of the polymer could limit the decrease in mechanical strength. This type of treatment is impregnated in the wood in an aqueous solution and the curing (150°C-24h, in the first approach) enables the polymerization. All the treatments developed showed that they brought significant improvements to beech wood. In terms of gain and stability indicators, a mass gain of about 40%, a bulking greater than 20% for air-dried wood, as well as a greater dimensional stability, the ASE, over 60%, and a total shrinkage-swelling divided by 3 was observed. Regarding the mechanical properties, they also saw significant changes, such as the stiffness increased by 30% to 60% (MOE) and the Brinell hardness up to 65%. However, the modified wood has lost its ductility and showed a brittle mode of failure with a modulus of rupture (MOR) reduced by almost 30%. In addition, measurement of the density profile by X-rays attenuation showed a heterogeneous distribution of the treatment in the board thickness, more concentrated at the surfaces of the sample than at the core. To reduce the severity of the treatment, the time-temperature relationship of the wood curing was studied by monitoring the reaction progress at different temperatures using TGA analysis as well as using catalysts and a pre-polymerized mixture, MaGNW. The results showed that a lowering of the curing time could be possible by a factor 3, from 24h to 8h, and thus be possible at 150°C with catalysts, although higher leaching is then observed from these treatments into the wood. A lowering of the curing temperature could be considered depending on the intended use of the beech. We then looked at the possibility of applying this treatment at the board scale (up-scaling). Several avenues have been studied to limit the heterogeneity of the treatment in the boards. These are the reduction of the board thickness, the addition of a low temperature drying phase before the curing phase, as well as the use of the pre-polymer mixture, removing the aqueous phase of the solution, aiming to fix the product in the wood as soon as possible during curing. The first two options demonstrated the most interesting results in improving the homogeneity of the treatment in the board thickness. As for the third option, it led to a densified material
Hild, Frédéric. "Synthèse de polyesters et polycarbonates : polymérisation en milieu homogène en vue d'une utilisation en milieu hétérogène permettant le recyclage de l'initiateur de polymérisation". Phd thesis, Université de Strasbourg, 2012. http://tel.archives-ouvertes.fr/tel-00832499.
Texto completo da fonteGoument, 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.
Texto completo da fonteIn 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
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.
Texto completo da fonteA 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