A Polyelectrolyte Sealant for Fuel Cells Based on Grafted Fluorcopolymers

The preparation of grafted copolymers for electrochemical devices by chemical graft copolymerization of acrylic acid and α, β, β-trifluorostyrene to a film fluorinated copolymer of hexafluoropropylene with vinylidene fluoride is described. The grafted copolymers contained carboxyl groups, and the sulfonation process was carried out for the additional introduction of ionogenic sulfo groups into the copolymer structure. The optimal conditions for conducting the process are determined, which make it possible to obtain grafted copolymers with a wide range of electrochemical and physicomechanical properties. The resulting products in the form of ion-conducting membranes can be used as parts of current sources and other electrochemical devices and have a specific volumetric electrical resistance of 0.46–1.41 Ω m, an exchange capacity of 1.45–1.62 meq/g, a moisture content of 25–62%, and a destructive stress of 0.82–1.08 MPa.