Abstract
Interchange reaction rates of poly(ethylene terephthalate)(PET) by $\beta$-phenylethyl alcohol, benzoic acid, and benzyl benzoate were examined at comparable temperatures. The extent of reaction was determined by measuring the molecular weight change of PET. Higher reaction rates were observed for phenylethyl alcohol and benzoic acid in comparison with benzyl benzoate. The activation energies calculated were 128.9 kJ/mol for the alcoholysis, 80.8kJ/mol for the acidolysis, and 227.7kJ/mol for the transesterification reaction. On the basis of the model interchange reaction, the hydroxyl end groups of PET were blocked with the benzoyl group, and PET poor in cyclic oligomer was obtained as a result of the blocking.