Fluorine containing self‐crosslinking acrylic latexes with reduced flammability and their application as polymer binders for heterogeneous cation‐exchange membranes

In this study, self-crosslinking core–shell latexes comprising copolymerized perfluorethyl groups and a novel flame retardant based on phosphazene derivative were prepared by the semi-continuous non-seeded emulsion polymerization of 2,2,2-trifluorethyl methacrylate, methyl methacrylate, butyl acrylate, methacrylic acid, and hexaallylamino-cyclo-triphosphazene as main monomers. For interfacial crosslinking, diacetone acrylamide was copolymerized into the shell layer of latex particles to provide sites for subsequent reaction with adipic acid dihydrazide. The heterogeneous cation-exchange membranes were obtained by dispersing commercial strong acid cation-exchange resin powder in the latex binder and casting the mixture followed by keto-hydrazide crosslinking reaction. It was found that the increased concentration of fluorine atoms and phosphazene units in the macromolecular structure of interfacially crosslinked emulsion polymers resulted in a significant enhancement of their flame resistance and shape stability in aqueous environment. Moreover, the easily prepared heterogeneous cation-exchange membranes based on latexes with higher amounts of fluorine and phosphazene units were shown to exhibit satisfactory physicochemical and electrochemical properties. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45467.