| abstract |
A polyelectrolyte film comprising as the main component a block copolymer which comprises, as components, a polymer block (A) having, as the main repeating units, units of an aromatic vinyl compound in which the hydrogen atoms bonded to the α-carbon atom may have been replaced with an alkyl group or optionally substituted aryl group and at least one of the hydrogen atoms directly bonded to the aromatic ring has been replaced with an alkyl group and a polymer block (B) forming a flexible phase, the polymer block (A) having ion-conductive groups; and a film-electrode assembly and a solid-polymer-type fuel cell each employing the polyelectrolyte film. The polymer block (A) may further contain a restrained phase or have been crosslinked. The electrolyte film is a polyelectrolyte film which is friendly to the environment, has high ion conductivity, satisfactory bondability to electrodes, and excellent moldability, and is less affected by methanol. It exhibits excellent performances when used in a solid-polymer-type fuel cell, in particular, a direct methanol fuel cell. |