Tribological responsiveness and mechanism of PDMS polymer and anti-wear h-BN as additives in base jatropha lubricant: Synergetic and antagonistic study

Abstract

Additives in various forms have drawn significant interest in tribological applications due to their superior tribological enhancing properties, notably in vegetable oil-based lubricants. Considering the advantages of vegetable oil-based lubricants over petroleum counterpart, industrial and domestic competition over edible lubricants has resulted in an increased focus on non-edible lubricants. To gain a better understanding of the synergistic and antagonistic properties of the two different additives, this study used a four-ball tribometer to investigate the tribological performance of jatropha oil-based lubricants combined with polydimethylsiloxane (PDMS) polymer and anti-wear hexagonal boron nitride (h-BN). Prior to the tribological test, physiochemical analysis was performed on the jatropha oil base and the two additions. The outcome produced outstanding behavior that is suitable for tribological enhancement. The frictional analysis revealed that wear scars lubricated with PDMS polymer, and h-BN nano lubricants, both separately and blended, had a lower coefficient of friction (COF), wear scar diameter (WSD), and surface roughness (Ra) than the base lubricant, but were more active under blended conditions due to their synergetic ability. The results also revealed that the BJ/h-BN/PDMS-C nano lubricant had the best friction reduction with a 35.23% reduction in COF, a 29.2% reduction in WSD, and a 63.78% Ra. The worn surfaces were analyzed to better understand the lubrication mechanisms; hence energy dispersive spectroscopy revealed the additives on the ball-worn surfaces. In conclusion, the results of this investigation indicate that the produced nano lubricants possessed outstanding tribological properties, which contributed to the coactive improved performance and creation of effective tribo-films.