Stress-Optical Coefficient of the Compatible Poly(styrene)-Poly(methyl methacrylate)-Benzene Solution System

Abstract

ABSTRACT:A ternary solution of poly(styrene)-poly(methyl methacrylate)-benzene has been studied rheo-optically. Shear viscosity of the PS-PMMA solutions measured by a capillary measuring apparatus is well fitted by the Hashin's blending rule. Flow birefringence 11n and orientation angle x of the solution in the steady shear flow is measured by the phase modulated flow birefringence (PMFB) technique. By comparing the shear viscosities measured in a capillary apparatus with the optical data from the PMFB, the stress-optical coefficients of the solution and of the pure PS and PMMA solutions are obtained. In a blend state, the value of stress-optical coefficient is able to be predicted as a simple linear additive relation with the values of two pure polymer species and the compositions. The stress-optical law is turned out to be applicable to compatible PS-PMMA-benzene solution system. KEY WORDS Ternary Solution / Poly(styrene)-Poly(methyl methacrylate)-Benzene / Stress-Optical Law / Stress-Optical Coefficient / Flow Birefringence / Phase Modulated Flow Birefringence / Polymer blend has been an important role in polymer science and technology because of its superior properties rather than those of homopolymers. The concept of physically blending of two existing polymers to obtain new products has not been fully understood. 1 Especially, an investigation of flow behaviors of the polymer blend system is one of the most interesting problems to be solved. So far, unfortunately, the development of a theoretical consideration for the polymer blends has been a very difficult work because of their complex behaviors. Therefore, an experimental study is an useful tool to understand the rheological properties of the polymer blends. the investigation of the rheological properties of the polymeric liquids under a certain deformation. 2 -5 This method can measure some rheological properties of the polymer materials such as the shear stress and the normal stress difference more accurately and easily rather than the mechanical measuring devices which have some shortcomings in measuring the rheological properties because of the inherent compliance of its force transducers. 2As one of the measuring techniques for the polymer system, the flow birefringence method has been considered as one of the most productive experimental techniques suitable for