Ionic copolymer, curable film precursor composition, film composition, and electronic device

A cationic copolymer comprises divalent monomer units: and wherein: each Ar1 independently represents a benzylidene group; each L independently represents a direct bond or wherein each R1 independently represents an alkyl group having from 1 to 4 carbon atoms, and each R2 independently represents an alkylidene group having from 1 to 6 carbon atoms, and each Z-represents a non-interfering anion; each Ar2 independently represents an optionally substituted divalent aryl ring, with the proviso that if L represents a direct bond, then Ar2 represents an optionally substituted cationic divalent aryl ring with Z-; each R3 independently represents H or an alkyl group having 1 to 6 carbon atoms; and each D independently represents a direct bond or Ar2, where adjacent D and L are not both direct bonds, and where if L is a direct bond, D is Ar2. The cationic copolymer may be free radiation curable and used in the membrane. 一种阳离子共聚物包含二价单体单元：和其中：每个Ar1独立地表示苯亚基；每个L独立地表示直接键或者其中每个R1独立地表示具有1至4个碳原子的烷基基团，并且每个R2独立地表示具有1至6个碳原子的烷亚基基