WATER-SOLUBLE COPOLYMERS .44. AMPHOLYTIC TERPOLYMERS OF ACRYLAMIDE WITH SODIUM 2-ACRYLAMIDO-2-METHYLPROPANESULFONATE AND 2-ACRYLAMIDO-2-METHYLPROPANETRIMETHYLAMMONIUM CHLORIDE

Low charge density ampholytic terpolymers of acrylamide with random distributions of sodium 2-acrylamido-2-methylpropanesulphonate and 2-acrylamido-2-methylpropanetrimethylammonium chloride have been synthesized by free radical polymerization in 0.5 M NaCl aqueous solutions. Terpolymer compositions were obtained by C-13 n.m.r. Low angle laser light scattering provided molecular weights and second virial coefficients which varied from 2.78 x 10(6) to 6.77 x 10(6) g Mol-1 and 1.31 to 2.95 ml mol g-2, respectively. Dilute solution properties of the terpolymers were measured with respect to composition, concentration and added electrolytes. Polyampholyte behaviour was observed for the polymer with as little as 0.5 mol% of each charged group and became significant when 7 mol% of each charged monomer was incorporated. At 12 and 15 mol% incorporation of each charged monomer, solution behaviour becomes complex consistent with the existence of intermolecular interactions at low ionic strengths and intramolecular associations at medium salt concentrations.