THERMOGRAVIMETRIC ANALYSIS OF POLYESTERS DERIVED FROM TEREPHTHALIC, TETRACHLOROTEREPHTHALIC AND RELATED DIACIDS WITH BISPHENOL-A

Abstract

The thermogravimetric behaviour of polyesters derived from terephthalic, tetrachloroterephthalic and related diacids, with -CH2- and -OCH2- as spacer groups with bisphenol A as diphenol, was studied by dynamic thermogravimetry. Polyesters derived from a diacid with an entirely aromatic structure degrade at higher temperatures than those derived from aliphatic diacids owing to the flexibility of the polymeric chain. Polyesters derived from tetrachloroterephthalic acid showed a higher thermal stability than that derived from terephthalic acid, but for the aliphatic polyesters, the chlorinated form showed a lower stability than those without chlorine atoms, probably because the influence of the aliphatic character is greater. The kinetics parameters of the thermal decomposition were determined by the Arrhenius relationship; in the range considered, all thc studied polyesters degrade in a single stage, but probably via complex reactions.