抄録
An alternating copolymer of maleic acid and m, p-methylstyrene was prepared and the pH-induced conformational transition in aqueous salts has been investigated by pH-titration, viscometric and optical measurements. The relationbetween the intrinsic viscosity and the degree of neutralization of the primary carboxyl group shows a transition from a compact form to an extended coil one. The values of ΔGt0, which is the standard free energy change of the transition, were calculated from the modified pH-titration curves in the range of NaCl concentration between 0.01M and 0.27M. Also, the transition curves were calculated from the pH data in terms of the coil fraction in the molecule. All results were compared with those for maleic acid-styrene copolymer and maleic acid-amethylstyrene copolymer studied previously, and the influence of methyl groups on the transition was discussed.
