Paul McKinley K, Raeside Matthew C, Gutekunst Will R
School of Chemistry and Biochemistry, Georgia Institute of Technology, 901 Atlantic Drive NW, Atlanta, Georgia 30332, United States.
ACS Macro Lett. 2024 Nov 19;13(11):1411-1417. doi: 10.1021/acsmacrolett.4c00556. Epub 2024 Oct 8.
Polythioesters are attracting increasing interest in applications requiring degradability or recyclability. However, few general methods exist for the synthesis of these polymers. This report presents a fast and versatile method for synthesizing polythioesters from readily available lactone feedstocks. The two-step process begins with the thionation of lactones to thionolactones, followed by the ring-opening polymerization of the thionolactones to polythioesters. Unlike previous methods that rely on harsh reagents to accomplish this transformation, we demonstrate that the mild tetrabutylammonium thioacetate is a competent initiator for polymerization. This method exhibits broad applicability, as demonstrated by the successful polymerizations of an unstrained 17-membered macrocycle and an N-substituted cyclic thionocarbamate. Furthermore, the generality of this scheme enables the synthesis of polythioesters with highly tunable properties, as demonstrated here by the synthesis of a set of polymers with glass transition temperatures spanning 180 °C. Finally, the polythioesters are efficiently depolymerized into the corresponding thiolactones.
聚硫酯在需要可降解性或可回收性的应用中越来越受到关注。然而，合成这些聚合物的通用方法很少。本报告介绍了一种从容易获得的内酯原料合成聚硫酯的快速且通用的方法。该两步法首先将内酯硫代化为硫代内酯，然后将硫代内酯开环聚合成聚硫酯。与以往依赖苛刻试剂来完成这种转化的方法不同，我们证明温和的硫代乙酸四丁铵是一种有效的聚合引发剂。该方法具有广泛的适用性，如无张力的17元大环和N-取代的环状硫代氨基甲酸酯的成功聚合所示。此外，该方案的通用性使得能够合成具有高度可调节性能的聚硫酯，如此处通过合成一组玻璃化转变温度跨度为180°C的聚合物所示。最后，聚硫酯可有效地解聚为相应的硫代内酯。
