Chemically stable hybrid polymer electrolyte membranes prepared by radiation grafting, sulfonation, and silane-crosslinking techniques

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

To prepare a crosslinked hybrid polymer electrolyte membrane (PEM) with high chemical stability, -styryltrimethoxysilane (StSi) was first grafted to ETFE film by preirradiation. Hydrolysis-condensation and sulfonation were then performed on the StSi-grafted ETFE films to give them crosslinks and proton conductibility, respectively. The crosslinks enhance the chemical and thermal stability of the PEM. The effect of the timing of the hydrolysis-condensation and the sulfonation method on the properties of the resulting hybrid PEMs such as ion exchange capacity, proton conductivity, water uptake, chemical stability, and methanol permeability were investigated to confirm their applicability in fuel cells.