College of Materials Science and Engineering, Donghua University, Shanghai, 201620, China.
Macromol Rapid Commun. 2021 Feb;42(3):e2000498. doi: 10.1002/marc.202000498. Epub 2020 Dec 18.
Flexible aliphatic poly(lactic acid) is introduced into polyethylene terephthalate through copolymerization to prepare biodegradable copolyester, which aims to solve the non-degradability of polyethylene terephthalate (PET) and realize the greening of raw materials. In this work, poly(ethylene terephthalate-co-lactic acid) random copolyesters (PETLAs) of lactic acid composition from 10 to 50% is synthesized via one-pot method. The chemical structure and composition, thermal property, and crystallization property of prepared PETLAs resin are characterized. The results shows that the introduction of LA segment forms random copolyester, and the flexible LA segment results in slight decrease in the glass transition temperatures (T ), melting point (T ), and crystallinity (X ) of the copolyesters. The thermal stability of PETLAs is better, and the initial decomposition temperature of PETLA-10 can reach 394 °C. The PETLAs resin exhibits good processability, and PETLAs fibers are prepared by melt spinning. The strength of PETLA-10 fiber can reach 260 MPa after drawing treatment, and the elongation at break can reach 130%. Taking advantage of their features, PETLAs as an innovative bio-based polymer are expected to achieve ecofriendly applications in the fields of fiber, plastic, and film.
通过共聚的方式将柔性脂肪族聚乳酸（PLA）引入到聚对苯二甲酸乙二醇酯（PET）中，制备可生物降解的共聚酯，旨在解决 PET 的不可降解性问题，实现原料的绿色化。本工作通过一步法合成了 LA 含量为 10%~50%的聚对苯二甲酸乙二醇酯-共聚乳酸（PETLA）无规共聚酯。对制备的 PETLA 树脂的化学结构与组成、热性能和结晶性能进行了表征。结果表明，LA 链段的引入形成了无规共聚酯，柔性的 LA 链段使共聚酯的玻璃化转变温度（T ）、熔点（T ）和结晶度（X ）略有降低。PETLA 的热稳定性更好，PETLA-10 的起始分解温度可达 394℃。PETLA 树脂具有良好的加工性能，可通过熔融纺丝制备 PETLA 纤维。经过拉伸处理后，PETLA-10 纤维的强度可达 260 MPa，断裂伸长率可达 130%。利用其特点，作为一种创新的生物基聚合物，PETLA 有望在纤维、塑料和薄膜等领域实现环保应用。
