화학공학소재연구정보센터
Advances in Polymer Technology, Vol.24, No.1, 1-13, 2005
Kinetics and mechanism of esterification of epoxy resin with methacrylic acid in the presence of tertiary amines
The synthesis of vinyl ester resins V-1, V-2, and V-3 was carried out using bisphenol-A based epoxy resin and methacrylic acid in the presence of triethyl-, tripropyl-, and tributyl-amines, respectively. The reaction follows first-order kinetics. The interaction between acid and amine was investigated by IR spectroscopy which shows absorptions corresponding to the formation of activated acid-catalyst complex. The specific rate constants, calculated by regression analysis, were found to obey an Arrhenius expression. The kinetic and thermodynamic parameters: activation energy, frequency factor, entropy, enthalpy, and free energy revealed that the reaction was spontaneous and irreversible with a highly ordered activated complex. The activation energy of the esterification of epoxy resin in the presence of tertiary amines increases in order V-1 < V-2 < V-3. The experimental results were explained by proposing a reaction mechanism and deriving the rate equation. (C) 2005 Wiley Periodicals, Inc.