Modulating Polymerization Thermodynamics of Thiolactones Through Substituent and Heteroatom Incorporation

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 (T-c). 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.

Automated summary

This report investigates the polymerization thermodynamics of thiolactone monomers and explores the effects of substitution patterns and sulfur heteroatom incorporation. Computational studies reveal the significance of conformation in modulating the enthalpy of polymerization, enabling high conversion rates at near-ambient temperatures.