Long-lived intermediates in radiation-induced reactions of alicyclic polyimides films

Park, J.*; Enomoto, Kazuyuki; Yamashita, Takashi*; Takagi, Yasuyuki*; Todaka, Katsunori*; Maekawa, Yasunari

Alicyclic Polyimide (A-PI) films were utilized as a substrate of radiation-induced polymerization to prepare PEM for fuel cells. We successfully prepared the A-PI- PEM by radiation-induced grafting of styrene into A-PI films and subsequent sulfonation. The obtained A-PI-PEM has higher ion conductivity and mechanical and thermal properties, compared with conventional PEM (Nafion). Furthermore, the long-lived intermediates in irradiated A-PI films were observed in the UV-VIS spectra. In comparison with the decay profile of ESR spectra of irradiated A-PI films, the initiation radicals (600, 420 nm) and radical anion (720 nm) can be characterized in terms of the graft polymerization mechanism of A-PI films.