Chemically Recyclable Poly(thioether-thioester)s via Ring-Opening Polymerization of Seven-Membered Thiolactones

Developing new sulfur-containing polymers with chemical recyclability is highly demanded as next-generation high-performance sustainable polymeric materials. Herein, we prepared two seven-membered thiolactone monomers (M1 and M2) with sulfur-incorporated at different positions. Both monomers displayed excellent reactivity towards ring-opening polymerization with >90% monomer conversion at room temperature. The resulting poly(thioether-thioester) products P(M)s exhibited high thermal stability and comparable mechanical properties (σB = ~30 MPa, ɛB = ~660%) to commercial low-density polyethylene. Chemical recycling of P(M1) to its monomer M1 could be accomplished with excellent yield and purity. Intriguingly, P(M1) could be applied for selective absorption and recovery of Au3+ with >99% efficiency by the exploit of chemical recyclability of P(M1).