Rheological Behavior and Extrudate Swell of Polypropylene/Silicon Carbide Composites

The rheological behavior and extrudate swell of polypropylene (PP)/silicon carbide (SiC) composites were investigated. Polypropylene-grafted-maleic anhydride (PP-g-MA) was introduced into blending system as a compatibilizer. The effect of silicon carbide loading and surface modification on the rheological behavior of PP/SiC composites were studied using a capillary rheometer and SEM analysis. The results showed that the composites exhibit pseudoplastic behavior as the shear stress and extrudate swell increased with increasing shear rate, while shear viscosity decreased. Moreover, an increasing elongation rate leads to reduce elongation viscosity. The addition of PP-g-MA in PP/SiC composites has significantly decreased the apparent shear stress, apparent shear viscosity and percentage of extrudate swell.