Enzyme-Catalyzed Synthesis And Properties Of Polyol Ester Biolubricant Produced From Rhodotorula Glutinis Lipid

Biolubricants do not cause the environmental pollution resulting from the manufacturing and use of mineral-based lubricants, but the commonly adopted chemical method of preparing biolubricants using expensive vegetable oils as raw materials is still environmentally and economically unsatisfactory. In this study, R. glutinis lipid with a high oleic-acid content was esterified with trimethylolpropane (TMP) by using the Candida sp. 99-125 enzyme in a solvent-free system, and the effect of the microbial oil with the high oleic-acid content on the performance of resulting biolubricants was investigated. The purpose of this study was to solve the problems of pollution caused by the chemical synthesis of biolubricants and of the uneconomical use of vegetable oils as raw materials. Further, this study aimed to improve the performance of biolubricants by using the microbial lipid with a high oleic-acid content. As a result of optimization of the reaction conditions, the yield of trimethylolpropane fatty acid triester (TFAT) reached 89.5%. The synthesized biolubricants had excellent low-temperature lubrication performance (pour point = - 45 degrees C), and the physicochemical performance reached the ISOVG-46 grade. The results of the high-frequency reciprocating friction test (HRFT) show that the products have better tribological properties than mineral-based lubricants of the same viscosity grade (friction coefficient = 0.085; average wear scar diameter = 187 mu m).