Development of polymer electrolyte membranes by two-step radiation processing for use in DMFC

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

To develop a highly chemically stable proton conducting membrane for use in direct methanol fuel cell (DMFC), doubly crosslinked membranes were successfully prepared by the combination of chemical crosslinking and radiation crosslinking. Four monomers consisting of m,p-methylstyrene, p-tert-butylstyrene, divinylbenzene, and 1,2-bis(p,p-vinylphenyl)ethane were first introduced into poly(ethylene-co-tetrafluoroethylene) (ETFE) films by means of-grafting process. Then, the multiple -crosslinking was performed for the ETFE base film containing grafted-chains and subsequent sulfonation. As a result, this proton conducting membrane showed a very low permeability compared with that of Nafion in high methanol feed concentration.