247 research outputs found

    Proton-conducting polymer electrolyte membranes based on fluoropolymers incorporating perfluorovinyl ether sulfonic acids and fluoroalkenes Synthesis and characterizations

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    International audienceThis paper presents the synthesis of new polymer electrolyte membranes based on fluoropolymers incorporating aromatic perfluorovinyl ether sulfonic acids. A novel synthetic route describing the preparation of perfluorovinyl ether monomer containing sulfonic functionalities, 4-[(alpha,beta,beta-trifluorovinyl)oxy]benzene sulfonic acid (TFVOBSA), is reported. The radical (co) and terpolymerization of 4-[(alpha,beta,beta-trifluorovinyl)oxy]benzene sulfonyl chloride (TFVOBSC) with 1,1-difluoroethylene (or vinylidene fluoride, VDF), hexafluoropropene (HFP), and perfluoromethyl vinyl ether (PMVE) is described. The terpolymers of TFVOBSC with VDF and HFP, or VDF and PMVE, were hydrolyzed and led also to original fluorinated terpolymers bearing sulfonic acid aromatic side-group. The terpolymers were characterized by 1H and 19F NMR spectroscopies, SEC, DSC and TGA. Membranes incorporating these functional fluoropolymers were prepared and the electrochemical (IEC, proton conductivity, swelling rates) properties were studied and discussed

    Synthèse, polymérisation et application de nouveaux monomères phosphonés

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    MONTPELLIER-BU Sciences (341722106) / SudocSudocFranceF

    Poly(diméthylsiloxanes) fonctionnalisés comme bases de copolymérisation et de greffage chimique (vers la synthèse de matériaux silicones (nano)structurés)

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    MONTPELLIER-BU Sciences (341722106) / SudocSudocFranceF

    Polymérisation radicalaire contrôlée de l'[alpha]-fluoroacrylate de n-butyle

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    MONTPELLIER-BU Sciences (341722106) / SudocSudocFranceF

    Update on fluoroelastomers: from perfluoroelastomers to fluorosilicones and fluorophosphazenes

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    International audienceA survey of the synthesis, properties and applications of fluoroelastomers is reported falling into two main parts. After describing commercially available (per)fluorocarbon elastomers, fluoro-phosphazenes and silicones, recent data on hybrid fluorosilicones containing longer chains (often fluorinated) between silicon atoms are supplied. The second part deals with well-architectured fluoroelastomers. First, fluorinated thermoplastic elastomers obtained either by sequential iodine transfer polymerisation of fluoroalkenes (leading to triblock copolymers) or by a two-step procedure involving a monomer bearing peroxide that generated macroperoxides which thus produced graft copolymers. Then, multiblock copolymers were achieved either from telechelic perfluoropolyethers or from polyhydrosilylation of telechelic non-conjugated diene polyimides with fluorinated polyhybrid siloxane bearing Si–H end groups leading to exceptional materials

    Fonctionnalisation d'huiles végétales et de leurs dérivés pour la formulation de nouveaux revêtements polyuréthanes agro-ressourcés

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    Les huiles végétales et leurs dérivés ont conduit à de nouveaux précurseurs agro-ressourcés utilisés pour la synthèse de polymères. Grâce au couplage thiol-ène, des polyols ont été obtenus par greffage du mercaptoéthanol directement sur les triglycérides insaturés. De la même manière, les esters méthyliques des huiles végétales ont permis la synthèse d'esters et d'amides diols pseudo-téléchéliques. Des polyols ont également été obtenus grâce à la réaction d'ouverture des cycles oxirane présents sur des huiles végétales époxydées. Différents acides carboxyliques ont permis d'introduire des fonctions hydroxyle sur les triglycérides. Ces différents synthons ont conduit à l'élaboration d'une large gamme de matériaux polyuréthanes, présentant des Tg variant de -10 C à 100 C. Le carbonate de glycérol, issu du glycérol agro-ressourcé, a également été utilisé pour l'élaboration de dicyclocarbonates, soit par estérification/trans-estérification à partir de diacides obtenus par greffage de l'acide thioglycolique sur plusieurs acides gras, soit par dimérisation à partir d'un dithiol commercial. Des polyuréthanes sans isocyanate ont ainsi été formulés à partir de ces nouveaux dicyclocarbonates, ouvrant la voie vers des polyhydroxyuréthanes totalement agro-ressourcés. Les précurseurs, ainsi que les matériaux qui en découlent, ont été caractérisés et certains ont fait l'objet de tests à l'échelle pré-industrielle.Vegetable oils and their derivatives were used to synthesize new precursors suitable for polymer synthesis. Mercaptoethanol was grafted onto unsaturated triglycerides by thiol-ene coupling to yield polyols. This functionalization was also applied to vegetable oil methyl esters, yielding ester and amide containing pseudo-telechelic diols. The second synthetic strategy used ring opening of epoxydized vegetable oils. The reaction between vegetable oil oxiranes and several carboxylic acids afforded a range of polyester polyols. Thus, the synthesized intermediates allowed to formulate various polyurethanes, which exhibited glass transition temperatures ranging from -10 C to 100 C. Moreover, either esterification/trans-esterification with fatty acid based diacids, synthesized by thioglycolic acid addition onto different fatty acids, or thiol-ene coupling with a commercial dithiol, were performed on glycerin carbonate, leading to new dicyclocarbonates. Isocyanate free polyurethanes were then obtained from those dicyclocarbonates, opening the way for fully biobased polyhydroxyurethanes. The new precursor, and the polymers therefrom, were deeply characterized and some of them were tested at a pilot scale.MONTPELLIER-Ecole Nat.Chimie (341722204) / SudocSudocFranceF
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