Preparation of anion-exchange membranes using ionizing radiation and their cell testing

Koshikawa, Hiroshi; Yamaki, Tetsuya; Asano, Masaharu; Maekawa, Yasunari; Yamaguchi, Susumu*; Asazawa, Koichiro*; Yamada, Koji*; Tanaka, Hirohisa*

Anion-exchange membranes based on poly(ethylene-co-tetrafluoroethylene) (ETFE) were prepared by the -ray graft polymerization of chloromethylstyrene (CMS) and the subsequent quaternization. The degree of grafting increased during the course of reaction for up to 8 h. We obtained higher degree of grafting as the pre-irradiation dose became higher. The highest degree of grafting reached 101% at a dose of 50 kGy for 8 h. The hydroxide ion conductivity was 0.044 S/cm at room temperature and a relative humidity of 100%. This value is higher than or comparable to that of the previous radiation-grafted anion-exchange membranes.