Lubricant properties of biodegradable rubber tree seed (Hevea brasiliensis Muell. Arg) oil

The rapid exhaustion of mineral reserves and the growing concern for the environment makes it essential to find a replacement for mineral oil lubricants and non-edible vegetable oils meets the requirements. The present work investigated the physicochemical, thermal and tribological properties of Rubber seed (Hevea brasiliensis Muell. Arg) oil (RSO), which is available in plenty in countries like India, Malaysia, Thailand, Peru and Eucador. Properties like iodine value, acid value, saponification value, pour point, cloud point, viscosity and viscosity index were estimated for characterization of the oil. The fatty acid analysis was carried out using quantitative GC-MS and it was found that linoleic, oleic and linolenic were the major unsaturated fatty acids. Thermo gravimetric analysis was performed and it was found that RSO remains thermally stable upto 250 °C. Dynamic, kinematic viscosity and the viscosity index were calculated. The coefficient of friction and the wear preventive characteristics of the oil were estimated using a four ball tester. It was seen that RSO has characteristics which make it well suited to be developed into a bio- lubricant. Its properties can be improved further with the addition of suitable additives.