Kinetics and mechanism of esterification of monoepoxies

The esterification of monoepoxy diluents (phenyl, cresyl, and butyl glycidyl ethers) and acrylic acid in presence of triphenylphosphine as catalyst was performed at 70 degrees, 75 degrees, 80 degrees, 85 degrees, and 90 degrees C, and it followed first-order kinetics. The reactivity of aromatic monoepoxies was found to be higher than aliphatic, due to the inductive effect of phenyl and butyl groups. The activation energy of the esterification of the monoepoxy increases as Pv < Cv < Bv and varies from 67 to 82 KJ/mole. The specific rate constants were found to obey the Arrhenius expression. The kinetic and thermodynamic parameters viz., activation energy, frequency factor, entropy, enthalpy, and free energy revealed that the reaction was spontaneous and irreversible, resulting in a highly ordered, activated complex. A suitable mechanism is proposed and discussed.