Effect of Molecular Weight on Polymer Blend Phase Separation Kinetics

摘要

The technique of excimer fluorescence has been used to study the effect of molecular weight on the kinetics of phase separation in polystyrene (PS)/poly(vinyl methyl ether) (PVME) blends. From the fluorescence results, which have been analyzed by assuming that demixing occurs by spinodal decomposition, the growth rate of the dominant concentration fluctuation has been determined for 10% and 50% PS blends with PS molecular weights of 100,000 and 1,800,000. At both compositions, the stable growth rate was found to decrease with increasing PS molecular weight. The observed effect was weaker than expected, presumably due to the polydispersity of the PVME.