ABSTRACT
The bio-based/environmentally friendly category is growing as sustainability considerations create market needs and performance capabilities of bio-based lubricants improve. With a wide range of bio-based lubricants in use and under development, this chapter focuses on vegetable-based, and within that category, soybean-oil-based. Soy-based lubricants are one of the oldest and newest categories. The use of vegetable oils as lubricants is well established. Compared with mineral oil lubricant base stocks, vegetable oils typically have a higher viscosity index, lower evaporation loss, and enhanced lubricity. Vegetable oils offer significant advantages in resource renewability, biodegradability, and performance properties compared with petroleum-based lubricants. Soy-based lubricants are noted for their enhanced lubricity and high viscosity index along with low evaporation loss and low flammability. Soybean oil as a lubricant base stock has low volatility due to the high molecular weight of the triglyceride structure and small viscosity change with temperature.
