Developing chemically recyclable polymers represents a greener alternative to landfill and incineration and offers a closed-loop strategy toward a circular materials economy. However, the synthesis of chemically recyclable polymers is still plagued with certain fundamental limitations, including trade-offs between the monomer's cyclizability and polymerizability, as well as between polymer's depolymerizability and properties. Here we describe the subtle O-to-S substitution, dithiolactone monomers derived from abundant feedstock α-amino acids can demonstrate appealing chemical properties different from those of dilactone, including accelerated ring closure, augmented kinetics polymerizability, high depolymerizability and selectivity, and thus constitute a unique class of polythioester materials exhibiting controlled molecular weight (up to 100.5 kDa), atactic yet high crystallinity, structurally diversity, and chemical recyclability. These polythioesters well addresses the formidable challenges of developing chemically recyclable polymers by having an unusual set of desired properties, including easy-to-make monomer from ubiquitous feedstock, and high polymerizability, crystallinity and precise tunability of physicochemical performance, as well as high depolymerizability and selectivity. Computational studies explain why O-to-S modification of polymer backbone enables dovetailing desirable, but conflicting, performance into one polymer structure.

中文翻译：

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O-to-S 替代使环化性、聚合性和可回收性相互矛盾：二硫内酯与双内酯

开发化学可回收聚合物代表了一种更环保的垃圾填埋和焚烧替代方案，并为循环材料经济提供了闭环战略。然而，化学可回收聚合物的合成仍然受到某些基本限制的困扰，包括单体的环化性和聚合性之间的权衡，以及聚合物的解聚性和性质之间的权衡。在这里，我们描述了微妙的 O-to-S 取代，源自丰富原料 α-氨基酸的二硫内酯单体可以表现出与双内酯不同的吸引人的化学性质，包括加速闭环、增强动力学聚合性、高解聚性和选择性，因此构成了一类独特的聚硫酯材料，具有可控的分子量（高达 100.5 kDa）、无规但高结晶度、结构多样性和化学可回收性。这些聚硫酯具有一系列不同寻常的所需特性，包括易于从无处不在的原料中制备单体、高聚合性、结晶度和物理化学性能的精确可调性，以及高解聚性和选择性。计算研究解释了为什么聚合物主链的 O-to-S 改性能够将理想但相互矛盾的性能结合到一种聚合物结构中。这些聚硫酯具有一系列不同寻常的所需特性，包括易于从无处不在的原料中制备单体、高聚合性、结晶度和物理化学性能的精确可调性，以及高解聚性和选择性。计算研究解释了为什么聚合物主链的 O-to-S 改性能够将理想但相互矛盾的性能结合到一种聚合物结构中。这些聚硫酯具有一系列不同寻常的所需特性，包括易于从无处不在的原料中制备单体、高聚合性、结晶度和物理化学性能的精确可调性，以及高解聚性和选择性。计算研究解释了为什么聚合物主链的 O-to-S 改性能够将理想但相互矛盾的性能结合到一种聚合物结构中。