| abstract |
A copolymer of (a) an unsubstituted 4-hydroxystyrene monomer and (b) a substituted 4-hydroxystyrene monomer of the formulan wherein A, B, C, and D are independently H or C₁ to C₃ alkyl and wherein at least one of A, B, C and D is C₁ to C₃ alkyl; and wherein said copolymer has a molecular weight of from about 800 to about 100,000; and wherein the mol ratio of monomer (a) to monomer (b) ranges from about 3:1 to about 1:3. |