Enhancement of the tribological and thermal properties of UHMWPE based ternary nanocomposites containing graphene and titanium titride

Abstract

Ultra-high molecular weight polyethylene (UHMWPE) generally does not have high resistance to wear and are characterised by poor thermal stability when exposed to long working condition. To address these shortcomings, this study used hybrid graphene nanoplatelets (GN) and titanium nitride (TiN) nanoparticles to significantly enhance the wear resistance and thermal stability of UHMWPE. The nanocomposites were prepared by solvent mixing and hot compression process. Scanning electron microscope showed uniform dispersion of the nanoparticles in the UHMWPE matrix. The developed UHMWPE showed improved wear resistance and thermal stability relative to the pure UHMWPE. For instance, the wear rate reduced from 6.7 × 10−3 mm3 N−1 m−1 and 3.67 × 10−2 mm3 N−1 m−1 for pure UHMWPE to 2.687 × 10−5 mm3 N−1 m−1 and 1.34 × 7 × 10−4 mm3 N−1 m−1 for UHMWPE–2 wt% GN–10 wt% TiN at applied loads of 10 N and 20 N respectively. This is about 100 % increment in wear resistance at the respective applied loads compared to the pure UHMWPE. The thermal stability of the fabricated nanocomposites was studied using the thermogravimetric analyser (TGA). The addition of nanoparticles significantly reduced the thermal decomposition of UHMWPE matrix. The enhanced properties of the UHMWPE–GN–TiN nanocomposites may be attributed to the network structures formed from the dispersion of the GN and TiN nanoparticles in the UHMWPE matrix with promoted molecular chains interlocking.