Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer reviewed journal
Publication Acceptance Date: 11/19/2006
Publication Date: 12/15/2006
Citation: Sharma, B.K., Adhvaryu, A., Erhan, S.Z. 2006. Synthesis of hydroxy thio-ether derivatives of vegetable oil. Journal of Agricultural and Food Chemistry. 54:9866-9872. 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 desirable commodities due to their eco-friendly nature. These additives 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 preparation of sulfur incorporated vegetable oils using thiols. The reaction monitoring, process optimization and characterization was done using various analytical techniques. Experimental conditions involving various thiols, solvent, catalyst amount, time and temperature were optimized for research quantity and laboratory scale-up. These biobased additives 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: Biobased additives are desirable commodities due to their eco-friendly nature. These additives can demonstrate physical and chemical properties comparable to those of conventional mineral oil based products. Sulfur incorporated triacylglycerol can function as an antiwear/antifriction additive for lubricants. The synthesis of four useful hydroxy thio-ether derivatives of vegetable oils, from commercially available epoxidized vegetable oil and common organic thiols, is reported in this paper. The common thiols used herein were 1-butanethiol, 1-decanethiol, 1-octadecanethiol, and cyclohexyl mercaptan. Currently, there is no reported literature describing the synthesis of hydroxy thio-ether derivatives of vegetable oil. The reaction was monitored and products confirmed by NMR and FTIR spectroscopies. Experimental conditions involving various thiols, solvent, catalyst amount, time and temperature were optimized for research quantity and laboratory scale-up. The synthetic process retains the vegetable oil structure, eliminates poly-unsaturation in the molecule, and adds polar functional groups on triacylglycerol. These products can be used as agriculturally based antiwear additives for lubricant applications.