Enhanced wear resistance of high-density polyethylene composites reinforced by organosilane-graphitic nanoplatelets

It is known that graphite has excellent lubricant properties due to the 2D graphene layers bonded via van der Waals forces. Thus, graphite nanoplatelets (GNPs) should have high lubricating efficiency during contact frictional movement of sliding parts. However, GNPs have rarely been used to improve the tribological properties of polymeric materials. In this study, we aimed to improve wear resistance of GNP-reinforced high-density polyethylene (HDPE) composites via the synthesis of organosilane-modified GNPs. Wear resistance of the HDPE/GNP composites was examined on a pin-on-disc wear testing apparatus under various sliding velocities. The results revealed that compared to the composites without filler surface modification, significant enhancements in wear resistance under different sliding velocities were realized in silanized-GNP-reinforced HDPE composites. In particular, 97% wear resistance improvement under 1.3 m s-1 sliding velocity was obtained. Furthermore, the organosilane-modified GNPs minimized the influence of sliding velocity on wear resistance of the composite and thereby maintained excellent wear resistance in a broad range of sliding velocities, and even at very high velocity (2.0 m s−1). Both superior wear resistance and good stability of wear performance at various sliding velocities suggest silanized-GNP/HDPE composites are promising materials with great potential for a wide range of tribological applications.