Biodegradable aliphatic/aromatic copolyesters based on terephthalic acid and poly(L-lactic acid): Synthesis, characterization and hydrolytic degradation

• Published in: Chinese journal of polymer science Vol. 28; no. 3; pp. 405 - 415
• Main Authors: Wang, Bing-tao, Zhang, Yan, Song, Ping-an, Guo, Zheng-hong, Cheng, Jie, Fang, Zheng-ping
• Format: Journal Article
• Language: English
• Published: Heidelberg Chinese Chemical Society and Institute of Chemistry, CAS 01.05.2010; Lab of Polymer Materials and Engineering, Ningbo Institute of Technology, Zhejiang University, Ningbo 315100, China; Lab of Polymer Materials and Engineering, Ningbo Institute of Technology, Zhejiang University, Ningbo 315100, China%Lab of Polymer Materials and Engineering, Ningbo Institute of Technology, Zhejiang University, Ningbo 315100, China%Institute of Polymer Composites, Zhejiang University, Key Laboratory of Macromolecular Synthesis and Functionalization,Ministry of Education, Hangzhou 310027, China; Institute of Polymer Composites, Zhejiang University, Key Laboratory of Macromolecular Synthesis and Functionalization,Ministry of Education, Hangzhou 310027, China
• Subjects: Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Condensed Matter Physics; Industrial Chemistry/Chemical Engineering; Polymer Sciences; Aliphatic/aromatic copolyesters; Direct melt polycondensation; Biodegradable
• ISSN: 0256-7679; 1439-6203
• DOI: 10.1007/s10118-010-9032-y

Biodegradable aliphatic/aromatic copolyesters, poly(butylene terephthalate- co -lactate) (PBTL) were prepared via direct melt polycondensation of terephthalic acid (TPA), 1,4-butanediol (BDO) and poly(L-lactic acid) oligomer (OLLA). The effects of polymerization time and temperature, as well as aliphatic/aromatic moiety ratio on the physical and thermal properties were investigated. The largest molecular weight of the copolyesters was up to 64100 with molecular weight distribution index of 2.09 when the polycondensation was carried out at 230°C for 6 h. DSC, XRD, DMA and TGA analysis clearly indicated that the degree of crystallinity, glass-transition temperature, melting point, decomposition temperature, tensile strength, elongation and Young’s modulus were influenced by the ratio between TPA and OLLA in the final copolyesters. Hydrolytic degradation results demonstrated that the incorporation of biodegradable lactate moieties into the aromatic polyester could efficiently improve hydrolytic degradability of the copolymer even though it still had many aromatic units in the main chains.