COMPARISON BETWEEN CRITICAL SHEAR RATES FOR FLOW-INDUCED HOMOGENIZATION OF POLYMER BLEND STUDIED BY RHEOMETRY AND FLOW-LIGHT SCATTERING

Abstract

The critical shear rate for flow-induced homogenization of a polystyrene/poly(vinyl methyl ether) blend with nearly critical composition in the phase-separated region near the phase separation temperature was studied by rheological and light scattering measurements under steady shear flows. The critical shear rate by rheometry was determined from the change in shear rate dependence of first normal stress difference as in a previous study. This critical shear rate was almost consistent with the critical shear rate by flow-light scattering at which the intensity deviates from the value in the phase-separated region.