Fabrication and tribological behavior of novel UHMWPE/vitamin-C/graphene nanoplatelets based hybrid composite for joint replacement

Abstract

Purpose This study aims to fabricate and investigate the tribological performance of ultra-high molecular weight polyethylene (UHMWPE)-based composite materials reinforced with 0.5, 1 and 2 weight percentage of graphene nanoplatelets (GNPs) while keeping the weight percentage of vitamin C constant at 2% for each composite. Design/methodology/approach In this paper, the composites were fabricated using hot pressing, and the dispersion of GNP/vitamin C/UHMWPE hybrid composite was investigated by X-ray diffraction. Experimental trials were performed according to ASTM F732 on a reciprocating sliding tribometer (pin-on-disc) at human body temperature of 37 ± 1 °C, for a load of 52 N, to assess the role of these fillers on the tribological properties of UHMWPE against Ti6Al4V counter body material under dry and lubricating (human serum) environment. Findings In this study, it has been observed that friction and wear behavior of the developed composites improve with increase in weight percentage of GNP, and human serum adheres to the surface of the composite pins upon sliding, resulting in the formation of a film, which results in better wear resistance of the composite pins under human serum lubrication than dry sliding. Scanning electron microscope was used to investigate the worn surface morphological examination of the composite materials. Specific wear rate of 0.76 × 10−7 mm3/Nm was attained for 2 Wt.% GNP-filled composite under human serum lubrication. Practical implications The results indicate the compatibility of the composite material used in this study and suggested the in vitro implant application. Originality/value The presented work includes novel study of synergistic effect of GNP (which acts as a solid lubricant) and vitamin C (added as an antioxidant) on the tribological performance of UHMWPE under dry and human serum lubrication.

Effect of the reduced graphene oxide on the tribological behavior of UHMWPE/rGO nanocomposites under sliding contact conditions

“…Major reduction in the wear rate for the 2 wt% of GNP [27] GO agglomerates exhibited greater wear resistance in in pin-on-drum abrasive wear tests and lower COF in reciprocating ball-on-plate tests with stainless steel ball counterface. The authors attributed the superior tribological behavior of the nanocomposites to a superlubricity phenomenon of GO agglomerates resulting from the slip between their flakes, which are supposed to be agglomerated in an organized manner and promoted low friction.…”

“…[25] The removal of the oxygen groups makes the rGO predominately hydrophobic, which can be an important feature for some engineering applications. [20,21] Several studies [5][6][7]11,26,27] have shown that the low content of graphene nanofillers into the UHMWPE matrix can reduce the wear rate and COF of the tribosystems under sliding contact conditions. Table 1 summarizes recent literature results on the tribological behavior of UHMWPE/graphene-based nanocomposites during sliding wear tests.…”

“…The literature referenced in Table 1 [5][6][7]11,26,27] indicates an improvement in the tribological behavior of the UHMWPE/graphene-based nanocomposites explained by the lubricating effect and the enhancement of mechanical strength due to the presence of 2D carbon nanomaterials. The lubricating effect is promoted by the thin-layered sheets structure of graphene nanofillers, which reduce the shear strength of the nanocomposite, whereas the mechanical strength is attributed to an efficient load transfer from the polymer matrix to the nanofillers under sliding contact conditions.…”

“…Several studies [ 5–7,11,26,27 ] have shown that the low content of graphene nanofillers into the UHMWPE matrix can reduce the wear rate and COF of the tribosystems under sliding contact conditions. Table 1 summarizes recent literature results on the tribological behavior of UHMWPE/graphene‐based nanocomposites during sliding wear tests.…”