SHEAR-INDUCED MIXING IN POLYMER BLENDS

Abstract

The effect of shear flow on phase separation in critical polymer blends is reviewed. For a low-molecular-weight blend, the response is in good agreement with the theoretical predictions of Onuki and Kawasaki. The break-up of large-scale critical fluctuations by the flow leads to a drop in the temperature T c at which phase separation begins. For a high-molecular-weight blend, the data suggest that the mode-coupling contribution to the decay rate of composition fluctuations is significant in both the miscible and immiscible phases. No shear-induced shift in T c is apparent at any temperature in the one-phase region away from the equilibrium critical point, consistent with mean-field statics.