POLYMER ELECTROLYTE, CROSSLINKED POLYMER ELECTROLYTE, POLYMER ELECTROLYTE MEMBRANE AND USE OF THE SAME

The present invention provides a polymer electrolyte, a crosslinked polymer electrolyte, a polymer electrolyte membrane and use of the same. The polymer electrolyte has a repeating unit represented by the following formula (1) in its molecule and an ion-exchange group in the molecule: wherein Ar represents an optionally substituted aromatic group; R 1 represents a hydrogen atom or an organic group; X represents a direct bond or a divalent group; n represents an integer of 1 to 3; and when n is 2 or more, the plurality of R 1 's may be the same as or different from each other.