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

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

Functional fluoropolymers for fuel cell membranes

International audienceVarious routes to synthesise functional fluoropolymers used in membranes for fuel cell applications are presented. They can be separated into three main families of alternatives. The first concerns the direct radical copolymerisation of fluoroalkenes with fluorinated functional monomers. The latter are either fluorinated vinyl ethers, a,h,h-trifluorostyrenes or trifluorovinyl oxy-aromatic monomers bearing sulfonic or phosphonic acids. The resulting membranes are the well-known Nafion\, Flemion\, Hyflon\, Dow\, Aciplex\ or BAM3G\. The second way deals with the chemical modification of hydrogenated polymers (e.g., polyparaphenylenes) with fluorinated sulfonic acid synthons. The third possibility concerns the synthesis of FP-g-poly(M) graft copolymers (where FP and M stand for fluoropolymer and monomer, respectively) obtained by activation (e.g., by irradiation with electrons, g-rays or ozone) of fluoropolymers, followed by grafting of the monomers. The most used M is styrene, and a further step of sulfonation was achieved onto FP-g-PS, leading to FP-g-PS sulfonic acid graft copolymers

Novel polymeric systems for lithium ion batteries gel electrolytes: II. Hybrid cross-linked poly(fluorosilicone-ethyleneoxide)

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