摘要 |
Provided are a modified vinyl alcohol (VA) having a reduced water content to exhibit a practically-required form stability, a producing method for the same, and an ion exchange membrane. (1) A copolymer (P) including, as structural units, a vinyl alcohol monomer unit (A), a vinylene monomer unit (B), and a polymer unit (C) having a polar group other than a hydroxyl group. (2) A method for producing the copolymer (P) including: providing a copolymer (P') including a vinyl alcohol polymer unit (A') and a polymer unit (C) having a polar group other than a hydroxyl group, and heat-treating the copolymer (P') under an acidic condition to form a polyene structure by dehydration so as to introduce a vinylene monomer unit (B). (3) An ion-exchange membrane containing as a main component a copolymer (PA) in which the polymer unit (C) having a polar group other than a hydroxyl group is a polymer unit (CA) having an ionic group. |