School of Chemistry and Biochemistry, Georgia Institute of Technology, 901 Atlantic Drive NW, Atlanta, Georgia 30332, United States.
School of Materials Science and Engineering, Georgia Institute of Technology, 771 Ferst Drive NW, Atlanta, Georgia 30332, United States.
ACS Macro Lett. 2022 Jul 19;11(7):895-901. doi: 10.1021/acsmacrolett.2c00319. Epub 2022 Jul 5.
A central challenge in the development of next-generation sustainable materials is to design polymers that can easily revert back to their monomeric starting material through chemical recycling to monomer (CRM). An emerging monomer class that displays efficient CRM are thiolactones, which exhibit rapid rates of polymerization and depolymerization. This report details the polymerization thermodynamics for a series of thiolactone monomers through systematic changes to substitution patterns and sulfur heteroatom incorporation. Additionally, computational studies highlight the importance of conformation in modulating the enthalpy of polymerization, leading to monomers that display high conversions to polymer at near-ambient temperatures, while maintaining low ceiling temperatures (). Specifically, the combination of a highly negative enthalpy (-19.3 kJ/mol) and entropy (-58.4 J/(mol·K)) of polymerization allows for a monomer whose equilibrium polymerization conversion is very sensitive to temperature.
开发下一代可持续材料的一个核心挑战是设计能够通过化学回收转化为单体的聚合物（CRM），从而轻易回到其单体起始材料的状态。一种新兴的单体类别——硫内酯，显示出高效的 CRM，其聚合和解聚速度很快。本报告详细介绍了一系列硫内酯单体的聚合热力学，通过系统改变取代模式和硫杂原子的引入来实现。此外，计算研究强调了构象在调节聚合焓方面的重要性，导致单体在接近环境温度下显示出高转化率为聚合物，同时保持低上限温度（）。具体来说，聚合焓（-19.3 kJ/mol）和熵（-58.4 J/（mol·K））非常负，使得单体的平衡聚合转化率对温度非常敏感。
