Hybridization of short glass fiber polypropylene composites with nanosilica and graphite nanoplatelets

The effects of various types and amounts of fumed silica and graphite nanoplatelets on the microstructure and thermomechanical properties of polypropylene composites containing 5, 10, and 20 wt% of short glass fibers have been analyzed. Hybrid composites were produced by melt compounding and compression molding. The aspect ratio of the short glass fiber decreased with the fiber loading and the nanofiller amount. The tensile strength and elastic modulus increased, while the elongation at break decreased as the content of both short glass fiber and nanofiller increased. A two-population model, based on the Halpin–Tsai and Tsai–Pagano composite theories, was used to predict the elastic modulus of the nano-micro hybrid composites. Experimental values appear to be reasonably consistent with model predictions. Tensile energy to break under impact conditions increased with the short glass fiber content but decreased with nanofiller amount. Moreover, storage modulus and creep stability were remarkably enhanced in short glass fiber composites by the presence of both nanofillers.