Chemical Modification and Tribological Evaluation of Pure Rice Bran Oil as Base Stocks for Biodegradable Lubricants

Vegetable oils act as a potential base stock for biodegradable lubricants. They possess better biodegradability, high flash point, high viscosity index and excellent lubrication properties. They also have some limitations like low thermal and oxidation stability, poor low-temperature properties and narrow range of viscosities. These limitations can be easily altered by chemically modifying vegetable oils or by using additives into these oils. This research work focused on the chemical modification of pure rice bran oil by epoxidation process. The epoxidized product of rice bran oil was then subjected to ring-opening process using different acids such as butanoic acid, benzoic acid and lauric acid. The tribological properties, flash temperature parameter and energy consumption in a four-ball tester for pure rice bran oil (RBO), epoxidized and ring-opened products of RBO were studied. It was noted that the evaluated properties of chemically modified products of RBO were better compared to pure RBO.