Organocatalytic Ring-Opening (Co)polymerization ofSix-Membered Monothiocarbonates for the Synthesis of Recyclable Poly(monothiocarbonate)s

Developing chemically depolymerizable polymers (CDPs) that can revert back to monomers is of great significance for realizing a circular polymer economy. Poly(thiocarbonate)s, sulfur analogs of polycarbonates, are a rather under-investigated group of sulfur-enriched polymers with high potential as CDPs. Here, we report a recyclable poly(monothiocarbonate) obtained via organocatalytic ring-opening polymerization of a six-membered cyclic monothiocarbonate. The resulting polymer exhibited a melting point up to 127 °C and a Young’s modulus of 305 MPa with a tensile stress of 23.2 MPa at 8.8% strain, while the analogue polycarbonate derived from trimethylene carbonate is amorphous with a low modulus (<100 MPa) under ambient temperature. Moreover, a successful copolymerization of 1,3-oxathian-2-one and 5,5-dimethyl-1,3-oxathian-2-one provided an access to precise tunability of thermomechanical performance of the poly(monothiocarbonate)s.