Local Solvent Effects on Configurational Characteristics of Polymer Chains: Poly(p-chlorostyrene) in Benzene

The effect of solvent on the configurational characteristics of the polymeric chain is studied for the poly(p-chlorostyrene)-benzene system. Among all possible configurations of benzene around the chain unit, two configurations, referred to as the parallel and perpendicular configurations, are found to lead to the lowest energy of interaction. The potential prevailing at the parallel configuration is calculated to be more favorable by 1.2 kcal/mol. Depending on the relative occurrence of these two competing configurations, new energy values are assigned to each rotational isomeric state of the chain structural unit. Configuration-dependent properties such as characteristic ratio, dipole ratio, and their temperature dependence are computed. The reduction in the dipole moment induced by the coupling of benzene with the chlorophenyl group is also included in the calculations. In general, satisfactory agreement with previous experimental measurements is achieved except for the positive temperature coefficient of dipole ratio reported at high temperature.