Polymer electrolyte membranes crosslinked by nitrile trimerization

摘要

A method is provided for making a crosslinked polymer electrolyte, typically in the form of a membrane for use as a polymer electrolyte membrane in an electrolytic cell such as a fuel cell, by trimerization of nitrile groups contained on groups pendant from the polymer. The resulting polymer electrolyte membrane comprises a highly fluorinated polymer comprising: a perfluorinated backbone, first pendent groups which comprise sulfonic acid groups, and crosslinks comprising trivalent groups according to the formula: The first pendent groups are typically according to the formula: -R¹-SO₃H, where R¹ is a branched or unbranched perfluoroalkyl or perfluoroether group comprising 1-15 carbon atoms and 0-4 oxygen atoms, most typically -O-CF₂-CF₂-CF₂-CF₂-SO₃H or -O-CF₂-CF(CF₃)-O-CF₂-CF₂-SO₃H.