Synthesis, characterization, and kinetics study of thermal decomposition of epoxidized soybean oil acrylate

The synthesis of epoxidized soybean oil acrylate (ESOA) from epoxidized soybean oil (ESO) had been carried out by reacting acrylic acid with the oxirane group in ESO. The acrylated ESO products were characterized using a variety of analytical techniques. The oxygen value, iodine value, and acid value were obtained to know the amount of unsaturation in the synthesized product. Infrared and proton NMR spectra were carried out to confirm the participation of oxirane group in the acrylation reaction. Free-radical initiators, benzoyl peroxide and tertiary butyl peroxy benzoate, were used for the curing of ESOA resin. Thermal decomposition kinetics of ESOA was studied by the methods of Ozawa, Kissinger, and Horowitz-Metzger, and the kinetic parameters were compared. The thermal decomposition data of the cured ESOA resin was analyzed by thermogravimetric analysis (TGA) at different heating rates. TG curves showed that the thermal decomposition of the ESOA system occurred in one stage. The apparent activation energies determined by the Ozawa, Kissinger, and Horowitz-Metzger methods are 122.69, 95.347, and 126.20 kJ/mol, respectively. The results show that there was a reasonably good agreement between the calculated activation energies for stage one in the above methods. (C) 2008 Wiley Periodicals, Inc.