Preparation of Sorbitol Palmitate by Organic Catalysis and Its Application for Base Oil Stabilization

Esters are excellent lubricants and high performance industrial fluids, but they are often costly. We prepared the ester sorbitol palmitate via an inexpensive phase-transfer catalysis method as an additive for the retardation of oil oxidation. The effects of the sorbitan palmitate content on the lubricant properties and oxidation stability of a base oil were determined. The addition of sorbitan palmitate to the oil retarded oxidation and enhanced the pour point depression. A novel method for inhibiting oxidation through the action of micellar cores was suggested. This micellar inhibition offers a new concept for the protection of lubricants against oxidative degradation.