The effect of fluidity of palm kernel oil with pour point depressant on coefficient of friction using fourball tribotester

Abstract

The growing awareness worldwide of the need to promote the use of renewable materials such as vegetable oils is due to increasing concerns about the damage to the environment that is being caused by the use of non-biodegradable mineral oils. Vegetable oils have the potential to replace mineral oils as a lubricant because of their specific properties, namely that they are non-toxic and biodegradable. The main problem with the use of vegetable oils is that they perform poorly at low temperatures. In this research, palm kernel oil (PKO), which behaves as a semi-solid, was used as a bio-lubricant by mixing it with different weight percentages of a pour point depressant (PPD) to investigate the performance of the pour point depressant and also to determine the effect on the lubricity of the bio-lubricant when it is blended with different percentages of PPD (5 wt.%, 10 wt.%, 20 wt.% and 30 wt.%). The experiment was conducted according to ASTM D4172 and ASTM D2783. The results of the experiment showed that at low temperatures the PKO samples with 20 wt.% PPD and 30 wt.% PPD performed well, where they were able to remain in a liquid form at a temperature of 15°C. From all antiwear test result, the coefficient of friction for the PPD sample shows poor tribological performance when adding PPD into the palm kernel oil.