Synthesis of aliphatic-aromatic random copolyester containing terephthaloyl repeating unit

Abstract

Synthesis of aliphatic-aromatic random copolyester containing terephthaloyl unit was studied with poly(butylene adipate-co-succinate-co-terephthalate) (PBAST) composed of similar amount of aliphatic and aromatic units. In the feed composition, amount of dimethyl terephthalate (DMT) and terephthalic acid (TPA) were varied. In the first test, aliphatic diacids and DMT were used as raw materials, and the result was compared with those of other tests. In the second test, all the diacid type of monomers, aliphatic diacids and TPA were used. However, the reaction rate was so slow that the reaction was stopped in esterification reaction. In the third and fourth test, aliphatic diacids, TPA were used, and at the same time a small amount of DMT was partially used. In these tests, overall reaction proceeded well. Intermediates formed by aliphatic component and DMT were expected to affect somewhat dissolving or reaction of TPA. Molecular weights, thermal properties, composition and randomness of synthesized samples were also measured and confirmed. The result shows that aliphatic-aromatic random copoyesters were synthesized well. This synthetic method of aliphatic-aromatic random copolyester is thought to be meaningful for the commercial melt polymerization, because this may be more homogeneous and economical.