Abstract
Epoxidized oils, epoxidized triacylglycerols, and epoxidized fatty acid methyl esters were made by reaction with performic acid formed in situ. The extent of epoxidation was ca. 95% for all of the epoxidized samples, as determined by 1H nuclear magnetic resonance. The epoxidized samples were reacted with an excess of acrylic acid for different reaction times. The acrylation reaction was found to have a first-order dependence on the epoxide concentration for all oils, pure triacylglycerols, and fatty acid methyl esters. However, the rate constant of acrylation was found to depend on the composition of the epoxidized material. The acrylation rate constant for 9,10-epoxystearic acid was 96 L2/(mol2·min). The rate constant of acrylation for the epoxides on 9,10,12,13-diepoxystearic acid was 60 L2/(mol2·min). The acrylation rate constant for the epoxides on 9,10,12,13,15,16-triepoxystearic acid was 50 L2/(mol2·min). Thus, the rate constant of acrylation increased as the number of epoxides per fotty acid decreased. Multiple epoxides per fatty acid decrease the reactivity of the epoxides because of steric hindrance effects, and the oxonium ion, formed as an intermediate during the epoxyacrylic acid reaction, is stabilized by local epoxide groups. These results were used to derive an acrylation kinetic model that predicts rate constants from fatty acid distributions in the oil. The predictions of the model closely match the experimentally determined rate constants.
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References
Borden, G.W., and O.W. Smith, Union Carbide Corp., Acrylated Epoxidized Soybean Oil Urethane Derivatives, U.S. Patent 4,025,477 (1977).
Khot, S.N., Rigid Thermoset Polymers from Acrylated Epoxidized Triglycerides, M.S. Thesis, University of Delaware, Newark, 1998.
Solomons, T.W.G., Organic Chemistry, 5th edn., John Wiley & Sons, New York, 1992, pp. 432–434.
Zaher, F.A., M.H. El-Mallah, and M.M. El-Hefnawy, Kinetics of Oxirane Cleavage in Epoxidized Soybean Oil, J. Am. Oil Chem. Soc. 66:698–700 (1989).
Zaher, F.A., and S.M. El-Shami, Oxirane Ring Opening by Formic Acid, Res. Ind. 36:191–194 (1991).
Bunker, S.P., The Synthesis and Characterization of Linear Polymers from a Fatty Acid Methyl Ester, M.S. Thesis, University of Delaware, Newark, 2000.
Swern, D., G.N. Billen, T.W. Findley, and J.T. Scanlan, Hydroxylation of Monounsaturated Fatty Materials with Hydrogen Peroxide, J. Am. Chem. Soc. 67:1786–1789 (1945).
Findley, T.W., D. Swern, and J.T. Scanlan, Epoxidation of Unsaturated Fatty Materials with Peracetic Acid in Glacial Acetic Acid Solution, —Ibid. 67:412–414 (1945).
Greenspan, F.P., The Convenient Preparation of Per-acids, —Ibid. 68:907 (1946).
Carey, F.A. Organic Chemistry, 2nd edn., McGraw-Hill, New York, 1992, pp. 652–654.
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Scala, J.L., Wool, R.P. The effect of fatty acid composition on the acrylation kinetics of epoxidized triacylglycerols. J Amer Oil Chem Soc 79, 59–63 (2002). https://doi.org/10.1007/s11746-002-0435-4
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DOI: https://doi.org/10.1007/s11746-002-0435-4