Despite their excellent, useful, and stable properties, thermoplastics are constantly subject to environmental risks because of their low degradability under thermal, chemical, and mechanical stresses. To overcome the aforementioned issues, we hereby introduce an eco-friendly camphor (Ct) cyclic diester. The Ct diester is designed as a monomer, including a ketal group from the Ct, and shows high thermal stability via a rigid spiro-ring and a bridged bicyclic structure. A series of polyester was synthesized using the Ct diester, including various types of diols and dimethyl terephthalate. PETxCty copolyesters showed appropriate thermal stability up to 414 °C and a high glass transition temperature. This thermal behavior led to amorphous regions as the Ct diester content increased. Regarding the proportion of the Ct diester in the polyester, it was sensitive to hydrolysis and contributed to the degradation of the polyester in acid buffer conditions.

Graphical Abstract

中文翻译：

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由樟脑和酒石酸制成的具有刚性环状二酯的生物可降解聚酯

尽管热塑性塑料具有优异、有用和稳定的特性，但由于它们在热、化学和机械应力下的低降解性，它们经常受到环境风险的影响。为了克服上述问题，我们特此介绍一种环保的樟脑 (Ct) 环二酯。Ct 二酯被设计为单体，包括来自 Ct 的缩酮基团，并通过刚性螺环和桥接双环结构显示出高热稳定性。使用 Ct 二酯合成了一系列聚酯，包括各种类型的二醇和对苯二甲酸二甲酯。PETxCty 共聚酯在高达 414 °C 的温度下表现出适当的热稳定性和较高的玻璃化转变温度。随着 Ct 二酯含量的增加，这种热行为导致无定形区域。关于聚酯中Ct二酯的比例，

图形概要