Dilute-Solution Properties of Polar Polymers: Poly-p-chlorostyrene and Poly-p-bromostyrene

Abstract

Light-scattering and intrinsic-viscosity measurements were carried out on fractions of poly-p-chlorostyrene and poly-p-bromostyrene in toluene at 30°C. Unperturbed dimensions were estimated from the Berry plots of second virial coefficients and also from the Stockmayer–Fixman plots of intrinsic viscosities. Values of the binary-cluster integral β per monomeric unit were determined by the two methods proposed in the previous paper; one is based on the use of the Yamakawa–Tanaka equation for the statistical-radius expansion factor, and the other the modified Stockmayer–Fixman plot. The results by the two methods were in excellent agreement with each other. The differences in β between poly-p-chlorostyrene and poly-p-methylstyrene, and between poly-p-bromostyrene and poly-p-methylstyrene in toluene, were analyzed using the theory of dilute solutions of polar polymers developed by Yamakawa and Rice on the basis of the cavity field and reaction field arguments. The agreement between theory and experiment was found to be satisfactory. The difference in β between polystyrene and poly-p-methylstyrene in toluene is also discussed. It is suggested that a complete theoretical calculation of the whole β should be based on the theory of simple liquids.