Disperse structure and mechanical properties of extruded polypropylene-polystyrene blends

Abstract

The authors analyse the influence of the viscoelastic properties of the components, the composition of the blends, preliminary mixing, the length of the capillary and shear stress in extrusion at 200°C on the particle size of the dispense phase, the size distribution and the rheological and strength properties of PP-PS blends. The particle size of the disperse phase (PP) in the cross section of the extrudates falls with increase in the ratio of the capillary length to diameter, rise in shear stress in the capillary, fall in the content of PP in the blend and on transition from the one- to two-stage process of blending. The strength and elastic modulus of the extrudates of the blends on bending significantly depend on the degree of dispersity and phase structure of the composites studied.