Submitted to: Journal of the American Oil Chemists' Society
Publication Type: Peer reviewed journal
Publication Acceptance Date: 11/14/2005
Publication Date: 3/1/2006
Citation: Sharma, B.K., Adhvaryu, A., Liu, Z., Erhan, S.Z. 2006. Chemical modification of vegetable oils for lubricant applications. Journal of the American Oil Chemists' Society. 83(2):129-136. Interpretive Summary: The uncertainty in supply of petroleum based products and their unfavorable impact on the environment has created a demand for eco-friendly lubricants. Vegetable oils are promising candidates for eco-friendly lubricants, because of advantages like naturally renewable resource, environmentally safe, good lubricity and viscosity-temperature characteristics. Vegetable oils have some shortcomings like poor low temperature flow properties and oxidation stability, which can be improved by chemical modification. This paper presents preparation of chemically modified vegetable oils using acid anhydrides. The reaction monitoring, process optimization and characterization was done using various analytical techniques. These fluids exhibit good oxidation stability and can be used in eco-friendly lubricant formulations such as hydraulic fluids, metal working fluids, crankcase oils, drilling fluids, two-cycle engine oils, wear resistant fluids, and greases. This approach will improve the agro-economy of the locally grown renewable resource with the new markets for soybean oil.
Technical Abstract: Due to unfavorable impact on the environment by mineral oil based lubricants, there has been a steady increase in the demand for biodegradable, environment friendly lubricants. However, development of a biodegradable base fluid that could replace conventional mineral oil is a big challenge. Vegetable oils are recognized as a fast biodegradable fluid and are thus promising candidates for the base fluid of the environment friendly lubricants. Vegetable oils have excellent lubricity, but poor oxidation and low temperature stability. This paper presents a series of structural modification of vegetable oils using anhydrides of different chain lengths. The reaction was monitored and products confirmed by NMR, FTIR and GPC analysis. Conditions were optimized for laboratory scale-up and potential bulk production. The base fluids exhibit superior oxidation stability and improved low temperature stability compared to vegetable oils.