Submitted to: Tribology International
Publication Type: Peer reviewed journal
Publication Acceptance Date: 7/10/2008
Publication Date: 8/21/2008
Citation: Sharma, B.K., Adhvaryu, A., Erhan, S.Z. 2008. Friction and wear behavior of thioether hydroxy vegetable oil. Tribology International. 42:353-358. Interpretive Summary: The uncertainty in supply of petroleum based products and their unfavorable impact on the environment has created a demand for eco-friendly biobased products. Biobased additives are eco-friendly and can demonstrate performance comparable to those of mineral oil based products. Sulfur containing vegetable oils can function as a friction reducing additive for biobased lubricants. This paper presents friction-wear studies on sulfur incorporated vegetable oils using thiols. Comparative tests with commercial antiwear additives demonstrate the effectiveness of these derivatives. The derivatives were found useful as agriculturally based antiwear additives for lubricant applications, 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. The approach will improve the agro-economy of the locally grown renewable resource with the new markets for soybean oil.
Technical Abstract: This work describes the tribochemical evaluation of vegetable oil based antiwear additive obtained through chemical modification. The sulfur was incorporated using a chemical reaction of epoxidized vegetable oil and common thiols, resulting in formation of a hydroxy thioether derivative of vegetable oils. The synthesis retains the vegetable oil structure, eliminates poly-unsaturation in the molecule, and adds polar functional groups that significantly improve adsorption on metal surfaces. These additives can be obtained from natural resources. The tribochemical behavior of sulfur incorporated vegetable oil was studied by measuring friction coefficient using ball-on-disk configuration and wear scar diameter using four-ball configuration. Comparative tests with commercial antiwear additives demonstrate the effectiveness of these derivatives. The derivatives were found useful as agriculturally based antiwear additives for lubricant applications.