Effect of an interface with solid on the component distribution in separated phases of binary polymer mixtures

Using the data on glass transition temperatures and phase diagrams of the unfilled and filled poly(vinyl acetate)–poly(methyl methacrylate) mixtures (1:1), the compositions of phases obtained after phase separation were calculated. Thermodynamic parameters of interaction between components in the unfilled and filled systems has been calculated. It was established that introduction of a filler increases the thermodynamic stability of the mixture (effect of compatibilization) and changes the compositions of separated phases. The observed effects were explained by the specific interaction of the mixture components with the active groups at the interface with solid and by the surface segregation of one of the components.