| abstract |
Disclosed is a polyarylene copolymer which can provide a membrane having high proton conductivity and excellent shape stability under high temperature and high humidity conditions. SOLUTION: A polystyrene-converted weight average molecular weight of 50,000 to 1,000,000 and a block having an ion exchange group, and a polystyrene-converted weight average molecular weight of 8,000 to 50,000 and a block having substantially no ion exchange group. A block copolymer comprising: The block having the ion exchange group includes a structural unit represented by the following formula (1), and the block having substantially no ion exchange group includes a structural unit represented by the following formula (2); A polyarylene block copolymer having an ion exchange capacity of 3.0 meq / g or more. (In the formula, Ar 1 represents an arylene group and Ar 2 represents an aromatic group. Ar 1 has at least one ion exchange group. X 1 represents an —O— group or an —S— group.) [Selection figure] None |