Wear behaviour of UHMWPE reinforced by carbon nanofiller and paraffin oil for joint replacement

- The nanocomposites were based on biomedical UHMWPE, oil and carbon nanofiller.
- UHMWPE was mixed with CNF by ball milling and extrusion.
- Wear behaviour and wet ability tests were performed with or without lubricant.
- The nanocomposites mixed by ball milling exhibited the best wear resistance.
- The 1.0 wt% of filler was optimal load for both mechanical and physical behaviour.

The majority of artificial joints incorporate biomedical grade Ultra High Molecular Weight Poly Ethylene (UHMWPE), whose wear is considered most important in controlling service time of the whole joint. The aim of this work was to improve wear resistance of UHMWPE through the addition of 0.5-2.0 wt% of Carbon Nano Filler (CNF) and 2% wt of Paraffin Oil (PO) using ball milling (BM) and extrusion techniques (EX). The wear tests on these nanocomposites were conducted by a pin on disc in dry (air) and wet media (simulated synovial fluid or artificial lubricant, and bovine synovial fluid or natural lubricant). Mechanical tests (tensile and hardness), physical analysis (calorimetric, density, wet ability, roughness) and morphological observations were also performed. The experimental results showed that natural lubricant provides the greatest reduction in wear rate while the largest one occurred in air. Furthermore, the BM mixed nanocomposites with a filler load of 1.0% exhibited the best wear resistance among all the samples with an improvement of 42%, 64% and 83% in air, artificial and natural lubricant, respectively. This is due to its higher ductility and thermal features, and lower wet ability in the two lubricants.

200