The initial stages of phase separation in the formation of semi-interpenetrating polymer networks (semi-IPN's) based on copolymer from styrene with divinylbenzene @VB)/ poly(buty1 methacrylate) (PBMA) were studied using an optical laser diffractometer. It was found that phase separation obeys the mechanism of spinodal decomposition. The peculiarity of phase separation in the system studied is due to the existence of a two-stage process. Each stage exhibits different interdiffusion coefficients, sizes of microheterogeneity areas and activation energies.

No abstract

Phase separation by semi-interpenetrating polymeric network formation based on the copolymer styrene-divinylbenzene (PS-DVB) and poly(buty1 methacrylate) (PBMA) was investigated by light scattering. The time for phase separation was measured as a function of the rate of the copolymerization reaction and of the composition of the initial blend. The time until the outset of phase separation decreases with increasing content of PBMA in the blend. The change in concentration of DVB does not influence the process of phase separation.

No abstract

SUMMARY The effect of a filler on the rate and energy of activation of phase separation was studied for binary poly(methy1 methacrylate)/poly(vinyl acetate) blends (system with LCST) using light scattering. It was found that the rate of phase separation of the filled blends at close quench depth AT = T-T, is much lower as compared with the unfilled one 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 separation and of the activation energy in filled systems is explained by the formation of a border layer at the interface with solid where molecular 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 filled blend.