Surface Modifications Induced in UHMWPE Based Nanocomposites during the Ageing in Simulated Synovial Fluid

Simulated synovial fluid (SSF) is a fluid that approximates the biological environment of a human joint because it is based on hyaluronic acid. The soaking of biomedical grade ultra high molecular weight polyethylene (UHMWPE) in SSF for longer periods results in ageing of the polymer, hardening the surface, and improving the surface roughness and wettability. This is because SSF progressively penetrates inside the polymer inducing oxidative degradation. Nanocomposite of UHMWPE reinforced with carbon nanofiller (CF) exhibits a higher resistance to the degradation of SSF compared to the control sample (pure UHMWPE).CNF, homogeneously distributed in the polymeric matrix, closes the pores among the grain boundaries of UHMWPE matrix, hindering the SSF insertion within it and its degrading action.