Synthesis of epoxy jatropha oil and its evaluation for lubricant properties

Vegetable oils are being investigated as potential source of environmentally favorable lubricants over synthetic products. Jatropha curcas L. oil (JO) identified as a potential raw material for biodiesel was explored for its use as a feedstock for biolubricants. Epoxidized jatropha oil (EJO) was prepared by peroxyformic acid generated in situ by reacting formic acid and hydrogen peroxide in the presence of sulfuric acid as catalyst. Almost complete conversion of unsaturated bonds in the oil into oxirane was achieved with oxirane value 5.0 and iodine value of oil reduced from 92 to 2 mg I2/g. EJO exhibited superior oxidative stability compared to JO. This study employed three antioxidants such as butylated hydroxy toluene (BHT), zinc dimethyl dithiocarbamate (ZDDC), and diphenyl amine (DPA) and found that DPA antioxidant performed better than ZDDC and BHT over EJO compared to JO. The lubricating properties of EJO and epoxy soybean oil (ESBO) are comparable. Hence, EJO can be projected as a potential lubricant basestock for high temperature applications.