Polymer, crosslinked polymer, composition for solid polymer electrolyte, solid polymer electrolyte and adhesive composition

Disclosed is a polymer comprising a block chain A composed of a random copolymer containing the repeating units (I) and (II) shown below and a block chain B containing the repeating unit (III) shown below in the order of B, A, B. Also disclosed are a crosslinked polymer obtained by a reaction between the polymer and a crosslinking agent, a composition for solid polymer electrolytes containing the polymer and an electrolyte salt, a solid polymer electrolyte and an adhesive composition.(In the above formulae, R -R , R , R , R -R respectively represent a hydrogen atom or a hydrocarbon group having 1-10 carbon atoms; R and R respectively represent a hydrogen atom or a methyl group; R represents a hydrogen atom, a hydrocarbon group or the like; m represents an integer of 1-100; R represents a hydrogen atom, a hydrocarbon group having 1-10 carbon atoms, a hydroxyl group or the like; R represents a hydroxyl group, a carboxyl group, an epoxy group or the like; and R represents an aryl group or a heteroaryl group.