Effect of Treatment of Natural Fillers on the Tribological Behaviour of Polymeric Materials

The study clarifies the mechanism of debris formation and adhesion on metal counterface. Polymeric materials filled with 30% sodium hydroxide 3, 4 and 5% treated and untreated coconut shell and bagasse fillers 100, 180 and 112 μm particle sizes, respectively, were produced. In the spectroscopic analysis, the increase in the transmittance level of a functional group indicates its reduction. 5% NaOH treated coconut shell filler and 4% NaOH treated bagasse filler had the highest reduced OH functional group in the treated fillers. Their carboxylic acid transmittances were 98.218% and 99.900%, respectively. The carboxylic acid transmittances of the untreated coconut shell and bagasse fillers were 95.218% and 95.954%, respectively. The unfilled polymers had a friction coefficient of 0.21, and their wear rates were in the order of 10-3mm3N-1mm-1. The filled polymers had a friction coefficient lower than 0.21 with varied wear rates. Polypropylene with sieved 100, 180 and 112 μm coconut shell and bagasse particles had wear rates in this order 0.010, 0.008 and 0.011 mm3N-1mm-1, and 0.009, 0.11 and 0.007 mm3N-1mm-1, respectively. The wear rate of the polyethylene with sieved 100, 180 and 112μm coconut shell and bagasse particles were in this order 0.012, 0.006 and 0.010 mm3N-1mm-1, and 0.008, 0.009 and 0.008 mm3N-1mm-1, respectively, in the same order with the particle sizes. The SEM micrograph of the wear track showed low adhesive and detached patchy shapes debris of the polymeric materials on the disc counterface. The larger filler particles caused agglomeration and low dispersion, especially in bagasse-filled polymeric materials. The suggestion, therefore, was the examination of the polymeric material on different metal counterfaces.