EFFECT OF FILLER ON KINETICS AND ENERGY OF ACTIVATION OF PHASE-SEPARATION IN POLY(METHYL METHACRYLATE) POLY(VINYL ACETATE) BLEND

The effect of a filler on the rate and energy of activation of phase s eparation was studied for binary poly(methyl methacrylate)/poly(vinyl acetate) blends (system with LCST) using light scattering. It was foun d that the rate of phase separation of the filled blends at close quen ch depth Delta T = T-T-s is much lower as compared with the unfilled o ne at close quench depth. The activation energy for the filled blends is lower than that of unfilled blends. The drop of the rate of phase s eparation and of the activation energy in filled systems is explained by the formation of a border layer at the interface with solid where m olecular packing is less dense and molecular mobility is restricted in comparison with unfilled polymer. Equal rates of phase separation or the equilibrium state may be achieved at higher quench depth for the f illed blend.