Evaluation of lubricant properties of vegetable oils as base oil for industrial lubricant

The possible insufficiency of oil resources in the future and the poor bio-degradability of mineral oil based lubricant resulted in the need of bio lubricant. Bio-based products are typically produced from vegetable oils. For the present study rice bran oil [RBO], jatropha oil [JO] and karanja oil [KO] are selected as the base oils for the industrial lubricant. Friction and wear characteristics are evaluated on four ball tester and the initial findings show that wear scar of RBO is lowest, this is because of the presence of natural anti-oxidants like gamma oryzanol. The coefficient of friction and wear of all the oils were evaluated as per ASTM D5183 and ASTMD 4172 respectively. Viscosity of the oils are tested on Brookfield rheometer and KO is having high viscosity when compared to other two oils but the change in viscosity with temperature is low for both RBO and JO. Chemical properties of the oils are conducted as per IS: 548 (Part 1) –1964. The iodine value for KO is less when compared to RBO and JO. Less iodine value is required to impart better oxidation stability. Thermogravimetric analysis showed that RBO is stable till 320 °C and KO, JO started degrading at 200 °C. The thermal properties of all the oils are measured and RBO has shown better properties at wide range of temperatures. The disadvantages of vegetable oils like oxidative stability need to be improved by adding additives and by chemical modifications.