生物可降解共聚物聚丁二酸/对苯二甲酸丁二醇酯(PBST)的序列结构及结晶性研究

制备了高分子量的聚丁二酸丁二醇酯,并通过与对苯二甲酸二甲酯的无规共聚调节其生物可降解性及力学性能,得到了具有优良机械性能和不同生物降解速度的一系列共聚物,并对共聚物序列结构、热力学性能、结晶性进行了研究.结果表明,该共聚物为无规共聚物,PBS和PBT分别结晶.共聚物的结晶熔点符合无规共聚物的Flory方程.

Studies on the Sequence Structure and Crystallinity of Poly(butylene succinate) Copolymers with Terephthalic Acid

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.