Novel aromatic copolymers based on a thiazolothiazole (TT) unit were designed and synthesized as proton exchange membranes for polymer electrolyte fuel cells. Even a small amount of the TT unit (0.1–1 mol%) considerably affected the sizes of the hydrophilic and hydrophobic domains of the membrane surface. Furthermore, the TT-based membranes exhibited higher proton conductivities and lower activation energies than those of the parent membrane under various relative humidity conditions.
- Shuntaro Amari
- Shinji Ando
- Takeo Yamaguchi
