Abstract: Aseries of high molecular weight polyesters, poly(butylene succinate)(PBS) and poly(butylene succinate-co-terephthalate)s(PBST), were obtained from succinic acid and/or dimethyl terephthalate reacting with 1,4-butanediol through a polycondensation process in the presence of a highly effective catalyst. The compostions and physical properties of both homopolyesters and copolyesters were investigated by ¹HNMR, gel permeation chromatography(GPC), differential scanning calorimetry(DSC), dynamic mechanical thermal analyzer(DMA), X-ray analysis and tensile test. Their number-average molecular weights are in the range of 1.25×10⁴-3.09×10⁴.The effect of copolymer composition on the thermal properties was investigated. The incorporation of rigid aromatic segments into aliphatic polyester was used for improving mechanical properties. Especially, the elongations at break(>500%) of the copolyesters(PBST) were much greater than that(80%) of the homopolyester(PBS).The results suggest that PBSTis a random copolyester and it has crystallinity in all the terephthalic acid contents.

Key words: Poly(butylene succinate)(PBS), Poly(butylene succinate-co-terephthalate)s(PBST), Polycondensation, Sequence structure, Crystallinity