Polymer cosolvent systems. Part 9.—The role of contact energies and free volume in two binary solvent mixtures for polystyrene

Abstract

The phase behaviour of polystyrene (3) in the binary solvent mixture dimethylcyclohexane(1)+ acetone(2) has been established. Cosolvent behaviour is evidenced by enhanced miscibility ranges at intermediate compositions of the mixture. Free-volume effects and contact-energy interactions have been examined in terms of the Patterson theory of polymer solutions. A similar analysis has been carried out on the system methylcyclohexane(1)+ diethylether(2)+ polystyrene(3) and a comparison of the results made. In contrast to the former system, cosolvent action in the latter is negligible, and this is rationalised in terms of a site model of cosolvency.