Rheological and Mechanical Properties of PC/HDPE/glass fiber Composites

Abstract

The rheological behaviour and mechanical properties of the polycarbonate/high density polyethylene/glass fiber (PC/HDPE/GF) composites have been studied, along with fiber-resin interface behaviour. Maleic anhydride grafted low density polyethylene (LDPE-g-MAH) was used as a compatibilizer in the composites. A study of the glass fiber-resin interface by scanning electron microscopy (SEM) and by etching techniques indicated that the dispersed phase polymer in the composites preferentially adhered to the glass fibers in the absence of LDPE-g-MAH. For the composites containing LDPE-g-MAH, this resin might play a decisive role in the adhesion of polymers to glass fibers. The types of adhered polymers were independent of PC/HDPE ratio. The rheological behaviour was studied using a capillary rheometer. The results showed that there was little relationship between the viscosities of the components and the types of polymer adhered to glass fibers. There was a critical shear rate at about 100s−1 for the viscosities of the composites. At shear rates lower than 100s−1, the glass fibers increased the viscosity of the composites; at shear rates higher than 100s−1, the glass fiber had little effect on the viscosity. The composites had a good balance of mechanical properties compared with PC/HDPE blends and PC/GF binary composites. LDPE-g-MAH in the composites could improve the reinforcement efficiency of the glass fibers and strengthen the adhesion between polymer matrix and glass fibers.