(86h) Synthesis and Tribological Properties of Bio-Based Lubricants from Vegetable Oils

The demand for bio-based lubricants has grown considerably in recent years due to increasing environmental awareness among the public, governments, and industries. In this study, pequi, soybean and castor oils were used for obtaining biolubricants. From pequi oil, a sample of bio-based lubricant was obtained through hydrolysis (AGLP, Pequi Free Fatty Acids) and esterification (BLS, Synthetic Biolubricant) routes, using a long-chain alcohol (2- ethylhexanol). Hydrolysis (AGLS, Soybean Free Fatty Acids), esterification (BL1), epoxidation (BL2) and oxirane ring opening (BLOR) reactions using 2-ethylhexanol were used to obtain soybean oil-based biolubricants. Finally, samples based on castor oil fatty acids (AGLM, Castor Free Fatty Acids) were obtained through esterification (ERIC), epoxidation (EPOXIRIC) and oxirane ring opening routes using water (ORWATER) and 2-ethylhexanol (OR2EHRIC) as nucleophilic agents. The reaction products were characterized via Fourier-Transform Infrared Spectroscopy (FTIR) and Nuclear Magnetic Resonance (NMR). The main physicochemical properties were determined according to standard ASTM methods. Frictional characteristics of the samples were obtained through tribological tests performed on a four-ball tribometer. Commercial mineral lubricant samples were used as references to evaluate the tribological behavior of the bio-based lubricants. Friction coefficients and Wear Scar measurements were compared to the mineral oil results. The obtained tribological properties indicate that the bio-based samples obtained from pequi, soybean and castor oil may be used as lubricant base oil in commercial applications.