The Effect of Zeolite on the Crystallization Behaviour and Tribological Properties of UHMWPE Composite BOON PENG Chang 1,a , HAZIZAN Md Akil 1,3,b and RAMDZIAH Bt Md Nasir 2,3,c 1 School of Materials and Mineral Resources Engineering, Engineering Campus Universiti Sains Malaysia, Nibong Tebal, Penang, 14300, Malaysia 2 School of Mechanical Engineering, Engineering Campus Universiti Sains Malaysia, Nibong Tebal, Penang, 14300, Malaysia 3 Cluster of Polymer Composite (CPC), Science and Engineering Research Centre (SERC), Engineering Campus, Universiti Sains Malaysia, Nibong Tebal, 14300, Malaysia a cbp87699@student.usm.my, b hazizan@eng.usm.my (corresponding author), c meramdziah@eng.usm.my Keywords: Zeolite, UHMWPE, Polymer Composite, Crystallinity, Tribology Abstract. In this work, the effects of adding different filler loadings (5–20 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. Introduction The popularity of ultra-high molecular weight polyethylene (UHMWPE) has raised when it was first used as potential materials for artificial joint implant applications in early 1960s. UHMWPE is a semicrystalline thermoplastic possess exceptional properties due to its extremely long chain entanglement. Among the prominent properties are its high toughness [1], chemical inertness and the highest wear resistance compared to other thermoplastics [2]. To date, it has been widely used in engineering applications such as total joint replacements bearing [3], lining for dump trucks, bumpers and siding for ships [1] plus many more. Despite its outstanding properties, the long term wear problem occurs after certain service period still remain a challenge, especially for total joint replacements. The modification of UHMWPE to enhance their properties is currently a hot research topic. The regularly applied approach is by incorporation reinforcement filler into the UHMWPE matrix. In literature, many studies using various reinforcement incorporated with UHMWPE matrix in order to enhance its tribological properties. This includes the addition of carbon fiber [4], carbon nanotube [5], zirconium [6], hydroxyapatite [7], alumina [8], ZnO [9] and others. Inorganic materials, such as metal oxide, ceramic, and mineral, have attracted significant research interest as polymer filler due to their excellent mechanical properties, ability to induce electrical and optical properties in polymer. Zeolites are an inorganic material based on tetrahedral AlO 4 and SiO 4 aluminosilicate with micro-porous structure. Its unique micro-porous structure makes it important in applications such as catalysts, separation process and cation-exchange materials in the last decade. Recently, there is a significant amount of research using different types Advanced Materials Research Vol. 812 (2013) pp 100-106 Online available since 2013/Sep/10 at www.scientific.net © (2013) Trans Tech Publications, Switzerland doi:10.4028/www.scientific.net/AMR.812.100 All rights reserved. No part of contents of this paper may be reproduced or transmitted in any form or by any means without the written permission of TTP, www.ttp.net. (ID: 202.170.51.225-25/11/13,05:27:47)