Silicon-containing polymer electrolyte hybrid membrane prepared by radiation-grafting of p-styrylsilane into poly(ethylene-co-tetrafluoroethylene) base film

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

In order to prepare a polymer electrolyte hybrid membrane with both high proton conductivity and high thermal stability, an aromatic vinyl monomer having a trimethoxysilyl group was first grafted into ETFE film by preirradiation. The styrylsilane-grafted film was then sulfonated, and finally hydrolyzed and condensed to introduce silane-crosslinking between the graft chains. Thus, a crosslinked proton-conducting polymer electrolyte hybrid membrane was obtained. 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 p-styrylsilane-grafted polymer electrolyte hybrid membrane are comparable to Nafion, and are superior to a styrene-grafted membrane.