Tribological investigations of trimethylolpropane trioleate bio-based lubricants

Abstract

Purpose The screening of lube oil performance prior to field trials is the most significant for the formulation of novel lubricants. This paper aims to investigate the efficacy of trimethylolpropane trioleate oil (TMPTO) based lubricants with different additives. Design/methodology/approach In this endeavor, initially five lubricating blends along-with TMPTO based oil with variable additives were evaluated for their tribological performances using ASTM standards. Out of these, the top three best-performing oils were further investigated for possible physical or chemical synergies among lube oils, additives and ball surface using SEM. The molecule structures of TMPTO based lube oils were confirmed using Fourier transform infrared spectroscopy (FTIR). Findings The wear preventive and extreme pressure characteristics of different TMPTO based samples were evaluated and compared for compatibility and synergy of additives. Morphological analysis of SEM images was used to understand the wear behavior of the worn surfaces. Practical implications Further investigation of TMPTO oil on its oxidation stability at high temperature and pressure to make it technologically competitive and commercially viable metal-working lubricant is suggested. Originality/value This paper highlights the tribo-effects of TMPTO to be rendered as a suitable lubricant for metal-cutting operations. The surface morphology of the worn-out surface significantly demonstrates the effect of loading conditions.