DIPOLE-MOMENTS OF POLY(PARA-CHLOROSTYRENE) CHAINS DETERMINED IN BENZENE, ISOPROPYL BENZENE AND NORMAL-PROPYL BENZENE

Abstract

Dipole moments of poly (p-chlorostyrene) were determined from dielectric and refractive index measurements performed on their dilute benzene, isopropyl benzene and n-propyl benzene solutions over a wide range of temperatures. Experimental results are expressed in terms of the dimensionless dipole moment ratios, D(x) = [mu-2]/x-mu-0(2). The temperature coefficients of dipole moments, d ln[mu-2]/dT were calculated. The presence and importance of the specific solvent-segment interactions are demonstrated by considering the temperature dependence of the dipole moment ratio in the vicinity of the theta temperature. These results are compared with dipole moments and temperature coefficients which were calculated by Bahar et al. using the appropriate rotational isomeric state model to study the local solvent effect for the poly (p-chlorostyrene)-benzene system.