IONIC COPOLYMER, CURABLE MEMBRANE PRECURSOR COMPOSITION, MEMBRANE COMPOSITION, AND ELECTRONIC DEVICE

A cationic copolymer comprises the divalent monomer units: wherein: each Arindependently represents phenylene; each L independently represents a direct bond or wherein each Rindependently represents an alkyl group having 1 to 4 carbon atoms, and each Rindependently represents an alkylene group having from 1 to 6 carbon atoms, and each Z represents a non-interfering anion; each Arindependently represents an optionally substituted divalent aryl ring, with the proviso that if L represents a direct bond, then Arrepresents an optionally substituted cationic divalent aryl ring accompanied by Z; each Rindependently represents H or an alkyl group having 1 to 6 carbon atoms; and each D independently represents a direct bond or Ar, wherein adjacent D and L are not both direct bonds, and wherein if L is a direct bond, then D is Ar. The cationic copolymer can be free-radially cured and used in a membrane.