Evaluation of the tribological performance and oxidative stability of a bi-functional lubricating oil additive prepared from corn cob extract

To meet the requirements of a circular economy, a class of sulfur- and phosphorus-free green bifunctional lubricating oil additives was developed based on corn cob extract as a naturally renewable biomass material. These additives can significantly enhance the friction-reducing, anti-wear properties, and oxidative stability of base oils. Results indicate that at an addition level of 4000 ppm, ternary polymer additive reduced the wear volume and surface roughness of steel friction pairs by 98.17 % and 97.63 %, respectively, and increased the oxidation induction period by 40.52 %. The improvement in tribological performance is attributed to the rigid ring structure preventing direct contact between friction pairs, and the chemical adsorption of carboxylic acid and anhydride groups with the metal, forming a dense friction film.