Polymer electrolyte hybrid membranes prepared by radiation grafting of -styryltrimethoxysilane into poly(ethylene--tetrafluoroethylene) films

Chen, J.; Asano, Masaharu; Maekawa, Yasunari; Yoshida, Masaru

In order to prepare a polymer electrolyte hybrid membrane with both high proton conductivity and high thermal stability, the -styryltrimethoxysilane was first grafted into ETFE film by -ray preirradiation. The grafted film was then sulfonated to attach sulfonic acid groups onto the aromatic rings of the graft chains, and finally hydrolyzed and condensed to introduce silane-crosslinking between the graft chains. The preparation conditions for grafting and sulfonation, and the properties of the resulting polymer electrolyte membrane, such as ion exchange capacity, proton conductivity, water uptake, and thermal stability, were investigated with respect to its application in fuel cells. It is concluded that the properties of the new polymer electrolyte hybrid membrane are comparable to Nafion, and are superior to a styrene-grafted membrane.