Reaction kinetics of esterification of phenol-cardanol based epoxidized novolac resins and methacrylic acid

The esterification reaction of phenol-cardanol based epoxidized novolac-vinyl ester resins was performed in the temperature range of 80–120 °C with an interval of 10 °C using a 1:0.9, epoxy-to-carboxylic group ratio in the presence of triphenyl phosphine as catalyst. The results based on kinetic study, indicated that the reaction followed first order kinetics. FT-IR analysis of vinyl ester resins revealed that addition esterification reaction between carbonyl and epoxy group took place and no side chain reactions occurred during the synthesis. A comparison of mechanism based rate equation and experimental data showed an excellent agreement. Finally, Arrhenius equation and activation energy were presented. The specific rate constants, based on linear regression analysis, were found to obey Arrhenius equation. The values of activation energy, frequency factor, enthalpy, entropy, and free energy of the reaction revealed that the reaction was spontaneous and irreversible and produced a highly activated complex.