Epoxidized vegetable lubricant enhanced by ionic liquid

Peanut oil lubricants were modified with the ionic liquid diethylmethylammonium methanesulfonate (IL) to produce novel biolubricants. Neat (Pn) and epoxidized peanut (EPn) oils with 1 wt% IL were studied in a stainless-steel/sapphire tribopair under pin-on-disc configuration. The highest viscosity was found for EPn+1%IL oil, and its outstanding tribological performance yielded a reduction in friction coefficient, and of up to 96.3 % in wear rate. X-ray photoelectron spectroscopy revealed the presence of IL and epoxidized oil tribofilm inside the wear tracks. The combination of thermal oxidation stability, viscosity, and tribological performance confirmed the potential use of ionic liquids as efficient additives in vegetable base oils. • Epoxidized peanut oil (EPn) showed high thermal oxidation resistance. • Peanut oils were blended with small proportion of ionic liquid (IL). • EPn+1%IL shows higher viscosity; lower friction and 96.3 % wear reduction. • Tribofilm development on a metallic surface ensured enhanced tribological performance.