A METHOD FOR PREPARING A RADIATION GRAFTED FUEL CELL MEMBRANE WITH ENHANCED CHEMICAL STABILITY AND A MEMBRANE ELECTRODE ASSEMBLY

摘要

It is the aim of the present invention to provide a method for preparing a membrane to be assembled in a membrane electrode assembly and a membrane electrode assembly which both have significant mechanical stability and appropriate fuel cell characteristics. These objectives are achieved according to the present invention by a method for preparing a membrane to be assembled in a membrane electrode assembly, such as a polymer electrolyte fuel cell, comprising the steps of : a) irradiating the base polymer film with electromagnetic and/or particle radiation in order to form reactive centers, i.e. radicals, within the said polymer film; b) exposing the irradiated film to a mixture of monomers amenable to radical polymerization comprising α- methylstyrene, methacrylonitrile and optionally divinylbenzene or diisopropenylbenzene as crosslinker in order to achieve the formation of a graft copolymer in said irradiated film. c) Sulfonation of the grafted film to introduce sulfonic acid sites providing ionic conductivity of the material.