The Effect of Anion Catalysts in Transesterification Reaction

에스테르 교환반응(交渙反應)에서 음(陰)이온 촉매(觸媒)의 영향(影響)

Transesterification reactions (methyl methacrylate with diethanolamine, ethylene glycol with dimethylphthalate) were kinetically investigated in the presence of zinc compound catalysts at $120{\sim}170^{\circ}C$ The amount of reactants was measured by gas chromatography. and the reaction rates also measured from the amount of reaction products and reactants upon each catalyst. The transesterification reactions were carried out under the first order conditions respect to the concentration of reactants, respectively, The overall reaction order was 2nd. The apparent rate constant (k') was found to obey first kinetics with respect to the concentration of catalyst. It shows that according to an increase in basicity of anionic species the rate constant increase, and that a linear relationship exists between ln k and pKa in transesterification reaction of methyl methacrylate with diethanolamine.