Electrical and mechanical properties of graphite/maleic anhydride grafted polypropylene nanocomposites

Abstract

The aim of this study was to investigate the effects of adding maleic anhydride grafted polypropylene (MA-PP) and graphite nanoplatelets (GNPs) into polypropylene. The tensile strength and flexural properties of the GNP/PP composite were enhanced with an increase in the MA-PP content and the GNP content. The maximum increase of mechanical properties was shown at 10wt.% of MA-PP having a constant GNP content of 8wt.% and at 20wt.% of GNP having a constant MA-PP content of 5wt.%, whereas a decrease in tensile strength and flexural properties was observed at 20wt.% of MA-PP. The impact strength was decreased by increasing the MA-PP content and the GNP content. The electrical resistivity of the GNP/PP composite exhibited an anisotropic characteristic due to the direction of the injection molding flow. Electrical resistivity of less than 106Ωcm regardless of the direction of the resin flow could be obtained by adding more than 20wt.% of GNP when the MA-PP content was 5wt.%. The differential scanning calorimetry results suggest that an increase of the GNP content makes it act as a nucleating agent and thus causes an increase in the crystallinity of the PP.