Comparison of the Tribological Properties of Environmentally Friendly Esters Produced by Different Mechanisms

Environmentally friendly esters are well-known lubrication materials used in pollution sensitive applications. Esters derived from renewable resources have inherent biodegradability, lubricity, an extremely high viscosity index, and non-volatility. However, their energy-intensive synthesis makes them relatively more expensive and less attractive for industry. Comprehensive studies have been conducted related to the lowering of energy requirement for ester synthesis. However, the tribological properties of these esters have not been compared. The current study for the first time is comparing the tribological properties of environmentally friendly trimethylolpropane (TMP) esters having different production paths. It was found that despite physicochemical properties are changing the method of TMP ester synthesis has a marginal effect on its tribological properties. Moreover, all the investigated esters were found to be compatible with the anti-wear additive.