Tribological performance of palm kernel oil with addition of pour point depressants as a lubricant using four-ball tribotester under variable load test

Abstract

The growing of worldwide trend for promoting the use of the renewable material such as vegetable oil is due to the increasing concern about environmental damage that caused by the use of mineral oil which is not biodegradable. Vegetable oil has a potential to replace mineral oil as a lubricant because of its specific properties that is non-toxic and biodegradable. The main problem in using vegetable oil is having poor low temperature performance. In this research palm kernel oil (PKO) that behave a semi solid phase is used as a bio lubricant mixing with different weightage percentage of poor point depressant (PPD) to investigate the low temperature behaviour performance and also to determine the effect of lubricity performance when blended with different percentage of PPD (5w%, 10wt%, 20wt% and 30wt %). The experiment is according to ASTM D4172 with variation load test. The result of the experiment show that for low temperature performance, PKO with 20wt%PPD (A2-20%) and 30wt%PPD (A2-30%) show great performance which can withstand 15° C. The sample A2-20% shows good lubricity performance in terms of coefficient of friction compare to the other sample. The lubricity performance in terms of wear scar diameter (WSD) it can see that the different percentage PPD do not affect the WSD properties of the pure palm kernel oil. The most consistent and the desired value of the sample in terms of surface roughness is A2-5% and A2-10% where the surface roughness value is stable through the entire load test.