Rheo-optical study on ternary solition blend (PS-PMMA-Benzene) system

Abstract

The birefringence, $\triangle$n, and the shear stress, $\sigma$, were measured on a steady shear flow a ternary solution with 9.5wt\% of poly (styrene)-poly(methyl methacrylate) in benzene. In order to confirm the linear stress-optical rule and to obtain stress-optical coefficient, both of the mechanical and optical methods are used for measuring shear stress $\triangle$n of the polymer solution. The weight fraction of PMMA of the solution was 0., 0.1, 0.2, 0.4, 0.6, 0.8, 1.0 respectively. Measurements of $\triangle$n were performed at various magnitudes of shear rate, $\gamma$, by PMFB (Phase-Modulated Flow Birefringence) method. The shear stress measured by capillary rheometer increased with blend ratio (the weight fraction of PMMA in the ternary solution). By relating $\triangle$n and x from stress-optical rule, stress-optical coefficients were obtained. The stress-optical rule for PS-PMMA-Benzene system was confirmed and stress-optical coefficients linearly increased with blend ratio.