Synthesis and Characterization of Eco‐Friendly Lubricants Exploring Epoxides and Polyol‐Esters Derived From <i>Madhuca indica</i> Seed Oil

ABSTRACT Petroleum‐based lubricants commonly used in machinery pose environmental risks due to their non‐biodegradable and non‐renewable nature. Switching to sustainable alternatives based on non‐edible oils instead of conventional lubricants is a viable approach to mitigate environmental conflicts. The present study aims to assess the suitability of Madhuca indica seed oil (Mahua oil) as a feedstock for environmentally friendly lubricants. Chemical modifications, specifically transesterification and epoxidation, were conducted on Mahua oil, and its lubricant properties were compared with that of a commercial lubricant. The study covers various aspects such as physicochemical, thermal, oxidative, rheological, and tribological properties. SiO 2 nanoparticles are also incorporated into the oil samples to study the resulting changes in tribological properties. Results show significant improvements in chemical stability and performance: acid and peroxide values decreased considerably post‐modification, and epoxidized Mahua oil (EMO) demonstrated superior thermal stability and tribological performance. With nanoparticle addition, the coefficient of friction (COF) and wear scar diameter (WSD) were reduced by 39.1% and 8.87%, respectively, indicating enhanced lubrication compared to unmodified Mahua oil. Both modified oils exhibited higher viscosity indices than the commercial fluid. These findings highlight that Epoxidation is more advantageous for chemically modifying vegetable oils, while transesterification proves particularly effective with oils high in free fatty acids. The resulting chemically modified Mahua oils show promising potential as alternatives to their petroleum‐based counterparts.