Effect of catalysts on the rate of esterification of terephthalic acid by ethylene glycol

Abstract

1. The esterification of TPA by ethylene glycol is accelerated both by conventional catalysts of this process and by catalysts used for polycondensation of bis-(β-hydroxyethyl)terephthalate (antimonic acid and organometallic compounds). The latter are more suitable for practical purposes because strong acids accelerate dehydration of ethylene glycol. 2. Esterification of TPA by ethylene glycol in the presence of the investigated catalysts is a zero-order reaction up to the moment of complete “dissolution” of TPA (up to a degree of completion of the reaction equal to 89–91%).