als which are part of a fused ring structure, Z is all of the aforementioned Z radicals except divalent aromatic hydrocarbon radicals, and halogenated divalent hydrocarbon radicals, R is an alkylene radical, a is an integer equal to 2 to 3, b is a whole number equal to 0 to 2, inclusive, and c is an integer equal to O to 3, inclusive, and the sum of b and c in said copolymers of (C) can have a va