| Summary: | In this study, a polyol ester from levulinic acid (LA) and trimethylolpropane (TMP) was synthesized by enzymatic catalysis in a solvent-free system. The total conversion of TMP reached up to 84% on average after lipase recycling for five times. The produced ester showed excellent lubrication properties, such as high viscosities at 40 °C (86.53 mm<sup>2</sup>/s) and 100 °C (8.91 mm<sup>2</sup>/s), a good viscosity index (49), a low pour point (−27 °C), and a high flash point (223 °C). The frictional wear behavior was evaluated on a four-ball test machine (FTM) by adding the ester into a reference mineral oil. The blend with 10% ester showed a smaller wear scar diameter (WSD) (0.62 mm) when compared with that of pure mineral oil (0.78 mm). The results demonstrated that the obtained ester has huge potential as biolubricant basestock.
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