In previous report, we discovered that a novel improvement technique to enhance the thermal properties of poly(L‐lactide)s (PLLAs) by terminal conjugation with 3,4‐diacetoxycinnamic acid (DACA). In this study, we clarified the mechanism of the enhancement of thermal stability by using commercial polyesters and polyethers. The effect of thermal improvement by the terminal conjugation of DACA on poly(DL‐lactide), poly(ε‐caprolactone), and poly(ethylene glycol) was almost the same as about 100 °C increase. The amount of residual tin catalyst, which enhances the thermal degradation of polyesters, was reduced at undetected level after the terminal conjugation of DACA probably due to the removal of tin during DACA conjugation process. Furthermore, the π‐π stacking interactions of DACA units and the chemical protection of terminal hydroxyl groups, which enhances intramolecular scission, were also important for the high thermal stability. We clarified that the extreme high thermal stability by DACA conjugation was induced by these above mechanisms. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011

中文翻译：

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商用聚酯和聚醚与生物基咖啡酸结合的高热稳定性机理

在以前的报告中，我们发现了一种新的改进技术，可通过与3,4-二乙酰氧基肉桂酸（DACA）的末端偶联来增强聚（L-丙交酯）（PLLA）的热性能。在这项研究中，我们阐明了使用商业聚酯和聚醚增强热稳定性的机理。DACA末端共轭对聚DL的热改善作用丙交酯，聚己内酯和聚乙二醇几乎与100°C时的温度升高相同。在DACA最终结合后，残余聚酯催化剂的量增加了聚酯的热降解能力，未检测到的水平降低了，这可能是由于DACA结合过程中锡的去除所致。此外，DACA单元的π-π堆积相互作用和末端羟基的化学保护作用（增强分子内断裂）对于高热稳定性也很重要。我们阐明，通过以上这些机制可以诱导DACA共轭具有极高的热稳定性。©2011 Wiley Periodicals，Inc. J Polym Sci A部分：Polym Chem，2011年