Performance evaluation of chemically modified vegetable oils towards development of biodegradable greener lubricant base stock

Vegetable oils such as linseed oil (LO), castor oil (CO), olive oil (OLO), soybean oil (SBO) and sunflower oil (SFO) were epoxidized and characterized using Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR) analysis. Reaction of epoxidized linseed oil with 2-ethylhexanol, dodecanol, n-octanol, 1-decanol and isodecanol in the presence of a catalytic amount of sulfuric acid provided ring-opened products. These ring–opened products of linseed oil exhibited better low temperature flow i.e. better pour point (PP) and high viscosity index (VI). Ring opened products with isodecanol and 2 ethyl hexanol showed better result compared to others. CO, OLO, SBO, SFO epoxide rings were also opened through the same procedure using isodecanol and the products exhibited high viscosity index and excellent low temperature flow as well. Ring opened products displayed better thermal stability when passed through thermogravimetric analysis (TGA) compared to mineral base oil. Better pour point, high viscosity index value, thermos-oxidative stability and better antiwear (AW) property make these products as an environmentally benign alternative to mineral lubricating oil.