Enhancement of surface tribology, mechanical, and electrical properties of UHMWPE via graphene nanoplatelets coating and electron beam irradiation

Abstract

This work aims to investigate the enhancement of tribological, mechanical, and electrical properties of ultra-high molecular weight polyethylene (UHMWPE) through surface modification via graphene nanoplatelet (GNP) coating combined with electron beam (E-beam) irradiation. UHMWPE substrates were dip-coated with 1 wt% GNPs and subjected to E-beam irradiation at doses ranging from 0 to 500 kGy. Among the tested conditions, irradiation at 100 kGy yielded the most favorable outcomes, including a reduced coefficient of friction (0.1793), improved tensile strength (28.94 MPa), increased elongation at break (58.35%), and the highest surface hardness (68 Shore D). Furthermore, the surface resistivity decreased markedly to 2.15 × 10⁸ Ω, indicating a significant improvement in surface conductivity. Fourier-transform infrared spectroscopy (FTIR) revealed the formation of carbonyl groups (CO), attributed to oxidative processes initiated by irradiation-induced free radicals. Scanning electron microscopy (SEM) images confirm enhanced GNP adhesion and uniform dispersion at moderate irradiation levels. However, excessive irradiation doses, exceeding 100 kGy, led to the degradation of both structural and functional properties due to polymer chain scission. These findings demonstrate that the synergistic integration of graphene coating and optimally tuned E-beam irradiation, particularly at 100 kGy, offers a promising strategy for developing UHMWPE-based materials with superior multifunctional performance for advanced tribological, mechanical, and electrical applications.