Enzymes are highly efficient, chemoselective, and sustainable biocatalysts, standing out as eco-friendly tools to advance the circular plastics economy. Herein, we explored enzymatic reactions of poly(ε-caprolactone)-poly(urethane) (PCL-PUs) in organic solvent under different reaction conditions using Novozym 435 (immobilized lipase) as the enzyme. PCL-PUs with triacetylated γ-cyclodextrin (TAcγCD)-based movable crosslinks (PCL-γCD-PU) not only exhibited excellent mechanical properties due to effective energy dissipation, but also efficient enzymatic degradation that was optimized for increases in TAcγCD content. Under reaction time control, molecular weight and mechanical properties of PCL-γCD-PU were enhanced by a novel enzymatic reinforcement strategy. Without sorting, the degraded products are versatile resources that can be enzymatically closed-loop recycled by switching reaction concentration or enzymatically upcycled into value-added polymers by mixing with selective substrates. The facile polymer structure design combined with enzymatic reactions is expected to provide a broad approach for toughening various polymeric materials and advancing their development as sustainable resources.

中文翻译：

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探索具有可移动交联的聚（酯）s-聚（氨基甲酸酯）的酶降解、增强、回收和升级回收


酶是高效、化学选择性和可持续的生物催化剂，是推进循环塑料经济的环保工具。在此，我们以 Novozym 435（固定化脂肪酶）为酶，探讨了聚 （ε-己内酯） -聚氨基甲酸酯 （PCL-PUs） 在不同反应条件下在有机溶剂中的酶促反应。具有三乙酰化γ-环糊精 （TAcγCD） 基可移动交联 （PCL-γCD-PU） 的 PCL-PU 不仅由于有效的能量耗散而表现出优异的机械性能，而且由于有效的酶降解而针对 TAcγCD 含量的增加进行了优化。在反应时间控制下，PCL-γCD-PU 的分子量和机械性能通过一种新的酶强化策略得到增强。无需分拣，降解产物是多功能资源，可以通过切换反应浓度进行酶促闭环回收，或者通过与选择性底物混合进行酶促升级回收为增值聚合物。简单的聚合物结构设计与酶促反应相结合，有望为各种聚合物材料的增韧和推动其作为可持续资源的发展提供广泛的方法。