Synthesis, Characterization, Tribological and Rheological Properties of Oleyl Oleate Based Biolubricant

Abstract

Oleyloleate (liquid wax ester) is a principal component of sperm whale bubbler oil has an important industrial application such as cosmetic, pharmaceutical and biolubricant. In this work, synthesis of oleyl oleate was carried out through esterification between oleoyl alcohol and oleic acidusing acidic heterogeneous catalyst, sodium hydrogen sulfate. About 95% of oleoyl oleate was produce at the optimal condition. The molecular structure of oleyl oleate has been confirmed by using FTIR, NMR and ESI-MS spectroscopies. The physicochemical properties of oleyl oleate were investigated. The results showed that the ester has pour point at -31 ± 1°C, flash point at 320 ± 2°C,viscosity index of 197.51 ± 1.4 and oxidative stability at 186.9 °C ± 1.8.Furthermore, tribological and rheological analysis of oleyl oleate were performed. Oleoyl oleate can be classified as a Newtonian fluid with having friction coefficient of 0.53 ± 0.08 at 100 °C operation condition. The presence of both ester functional group and long chaincarbon moiety in oleyl oleate structure has a positive impact on wear protection thus plausible to be use as general purpose industrial biolubricant.