| abstract |
PROBLEM TO BE SOLVED: To provide a polymer electrolyte membrane for a fuel cell, a gas sensor, which has excellent ion exchange capacity and proton conductivity, and further improved dimensional change upon water absorption, water resistance and methanol permeability compared to conventional sulfonated polyimide, To provide a crosslinked sulfonated polyimide that can be suitably used for an ion exchange resin or the like. A cross-linked sulfone obtained by crosslinking an acid-terminated sulfonated polyimide having a repeating unit represented by the following chemical formula (1) and having both ends of an aromatic tetracarboxylic acid component residue with a trifunctional or higher aromatic amine compound. Polyimide. [Chemical 1] [Wherein Ar 1 and Ar 4 are tetravalent groups having an aromatic ring, and Ar 2 is a divalent group having an aromatic ring substituted with one or more sulfonic acid groups or derivatives of sulfonic acid groups. Ar 5 is a divalent group having an aromatic ring that does not use a sulfonic acid group or a derivative of a sulfonic acid group as a substituent, l is an integer of 1 or more, and m is 0 or an integer of 1 or more. . ] [Selection figure] None |