THE EFFECT OF PROCESSING HISTORY OF POLY (METHYL METHACVYLAYE)-POLY (VINYL-ACETATE) MIXTURE ON THE MISCIBILITY OF COMPONENTS AND THE STRUCTURE OF THE SYSTEM

The concentration dependence of the Gibbs free energy of mixing PMMA w ith PVA was calculated for the entire concentration range on the basis of the data of static sorption of chloroform vapor by the films of PM MA, PVA, and their mixtures. The results obtained show that the system is a metastable one, and, depending on the processing history, behave s as either a homophase or a two-phase system. Phase separation upon h eating is characterized by a binodal with a lower critical solution te mperature; the structural transition in a single-phase system occurs i n the range of concentrations, where the concentration dependence of t he Gibbs energy of mixing is convex, witnessing reduced interaction be tween the components.