(170d) Assessment of Tribological Properties and Oxidative Stability of Bio-Based Lubricant from Pequi Oil (CARYOCAR BRASILIENSIS)

Bio-based lubricants are environmentally preferred to petroleum-based lubricants because they have greater biodegradability and are less toxic. Other advantages include very low volatility due to the high molecular weight and excellent viscosity properties with temperature variations. In this study, samples using pequi oil (Caryocar Brasiliensis) were obtained by hydrolysis and esterification reactions, using 2-ehtylhexanol. The oxidative stability was measured using Rancimat technique at 110ºC. The induction period of 5.44±0.19 h was observed for the synthesized samples. Tribological tests in a four-ball configuration were performed to evaluate the lubricating behavior. A comparison of the Stribeck curve of the bio-based sample with that of a mineral hydrotreated basestock oil showed that the samples from pequi oil had a lower friction coefficient at all the sliding speeds studied. The friction coefficient of the bio-based sample was 30.7% lower than mineral hydrotreated basestock oil. The wear scar diameters were 0.371 mm for the bio-based samples and 0.195 mm for mineral oil. These results indicate that a bio-based samples obtained from pequi oil may be potentially used as a basestock oil since it presents a satisfactory tribological performance.