Metathesized castor oil acylated derivatives: lubricants base stocks with low pour points and superior anti-wear properties

Abstract

Castor (Ricinus communis) oil containing ricinoleic acid 89% was self-metathesized in the presence of Grubbs' second generation catalyst (0.025 mmol), followed by epoxidation and insitu hydroxylation using Prilezhaev dihydroxylation method to obtain hydroxylated derivatives in 93% yields. MALDI study has shown that the metathesized products comprised of a mixture of monomer, dimer and trimer metathesized products. The hydroxylated derivatives were acylated using acetic, propionic, butyric and hexanoic anhydrides in 85-90% yields. The acylated base stocks being highly branched and of high molecular weights exhibited very low pour points (− 30 to − 40 °C) and broad viscosity ranges 45.5 cSt to 60.0 cSt at 40 °C, high viscosity indices , excellent anti-wear properties (0.52-0.69 mm), good thermal and oxidative stabilities along with high load carrying capacities (165-184 kg) suitable for multi-range industrial applications. These base stocks can be used with the addition of minimum additives during the formulation.