Performance of polymeric viscosity improver as bio- lubricant additives

Abstract

Purpose: The purpose of this paper is to study the influence of polymeric viscosity improver on the tribological performance of palm kernel methyl ester (PKME). Design/methodology/approach: Tribological performances of the PKME added with the various concentration of ethylene-vinyl acetate copolymer (EVA) were evaluated using four-ball tribotester under extreme pressure condition. The morphologies of the worn surfaces were observed by using the optical microscope. Findings: The addition of polymeric viscosity improver (EVA copolymer) has produced positive results towards the tribological properties of PKME. In total, 4 per cent of EVA copolymer is found as the optimum concentration by improving the friction reducing properties and anti-wear behaviour due to the formation of film thickness between two rubbing surfaces. Originality/value: This work might contribute to the development of vegetable oils as a new source of environmental-friendly lubricant.