Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer reviewed journal
Publication Acceptance Date: 9/4/2008
Publication Date: 9/11/2008
Citation: Erhan, S.Z., Sharma, B.K., Liu, Z., Adhvaryu, A. 2008. Lubricant Basestock Potential of Chemically Modified Vegetable Oils. Journal of Agricultural and Food Chemistry. 56:8919-8925. 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 their advantages as a naturally renewable resource, environmentally safe, and good lubricity. Vegetable oils have some shortcomings like poor low temperature flow properties and oxidation stability, which can be improved by chemical modification. This paper presents the study of modified soybean oil for their potential lubricant application. Important lubricant properties such as oxidation stability, low temperature flow properties and friction wear properties were studied. The lubricants were formulated using modified soybean oil and the additives showed superior properties. These formulations have potential applications in the industrial lubricant sector. The current approach will improve the agro-economy of the locally grown renewable resource with a new market for soybean oil.
Technical Abstract: The environment must be protected against pollution caused by lubricants based on petroleum oils. The pollution problem is so severe that approximately 50% of all lubricants sold worldwide end up in the environment via volatility, spills, and total loss applications. This threat to the environment can be avoided by either preventing undesirable losses, reclaiming and recycling mineral oil lubricants; or using environmentally friendly lubricants. Vegetable oils are recognized as rapidly biodegradable and are thus promising candidates as base fluids in environment friendly lubricants. Lubricants based on vegetable oils display excellent tribological properties, high viscosity indices and flash points. To complete with mineral oil based lubricants, some of their inherent disadvantages, such as poor oxidation and low temperature stability must be corrected. One way to address these problems is chemical modification of vegetable oils at the sites of unsaturation. After a one step chemical modification, the chemically modified soybean oil derivatives were studied for thermo-oxidative stability using pressurized differential scanning calorimetry and thin film micro-oxidation test; low temperature fluid properties using pour point measurements; and friction-wear properties using four-ball and ball-on-disk configurations. The lubricants formulated with chemically modified soybean oil derivatives exhibit superior low temperature flow properties, improved thermo-oxidative stability, and better friction and wear properties. The chemically modified soybean oil derivatives having diester substitution at the sites of unsaturation have potential in formulation of industrial lubricants.