Preparation and Properties of Lubricant Base Stocks from Epoxidized Karanja Oil and Its Alkyl Esters

Abstract

Lubricant base stocks of epoxidized oil and its alkyl esters namely epoxidized karanja fatty acid methyl, butyl, 2-methyl-1-propyl, and 2-ethylhexyl esters were synthesized from renewable nonedible source karanja oil (<i>Pongamia glabra</i>). The reaction was carried out using peroxy formic acid (HCOOH) generated <i>in situ,</i> 30 wt % aqueous hydrogen peroxide (H₂O₂) by monitoring oxirane oxygen value. The optimized conditions to obtain epoxidized products were oil/ester: HCOOH: H₂O₂ (1:2:8/1:1.5:3 mol/mol/mol). The epoxidized products were obtained in 90–97% conversion by GC analysis. All the products were characterized by GC, GC-MS, IR, ¹H NMR spectral studies. The synthesized products were evaluated for physicochemical and lubricant properties. Based on viscosity index all the products belong to group III, category of base fluids as per API classification. Expecting pour point values that are on higher side, other lubrication properties such as viscosity, VI, flash point, Cu corrosion value, and air release value were found to be good