The Effect of Zeolite on the Crystallization Behaviour and Tribological Properties of UHMWPE Composite

Abstract

In this work, the effects of adding different filler loadings (520 wt%) of zeolite to the ultra-high molecular weight polyethylene (UHMWPE) matrix on the crystallinity behaviour and tribological properties were studied. The zeolite/UHMWPE composites were fabricated using hot compression moulding. The crystallization behaviour was investigated using differential scanning calorimetry (DSC). The tribological properties were monitored using a Ducom TR-20 pin-on-disc tester under different sliding speeds of 0.209 ms-1 and 0.419 ms-1 and with various applied loads of 5, 10, 15, 20, 25, 30 and 35 N. The worn surfaces of the zeolite/UHMWPE composites were observed under the scanning electron microscope (SEM). The results showed that the addition of zeolite into UHMWPE matrix can effectively enhance the percentage crystallinity of the UHMWPE. 15 wt% zeolite-reinforced UHMWPE composites show the increase of 47% in percentage crystallinity as compared to pure UHMWPE. The wear mass loss of the composites was found to be reduced by the incorporation of zeolite in UHMWPE. In addition, the average coefficient of friction (COF) was also found to decrease with the addition of zeolite. The lowest average COF was obtained by 20 wt% zeolite reinforcements into UHMWPE. Shallower grooves and smoother worn surfaces were observed for zeolite/UHMWPE as compared to pure UHMWPE.