Chemically recyclable poly(thioether-thioester)s via ring-opening polymerization of seven-membered thiolactones†

Developing new sulfur-containing polymers with chemical recyclability as next-generation high-performance sustainable polymeric materials is in high demand. Herein, we prepared two seven-membered thiolactone monomers ( and ) 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()s exhibited high thermal stability and comparable mechanical properties (σ_B = ∼30 MPa, ε_B = ∼660%) to commercial low-density polyethylene. Chemical recycling of P() to its monomer could be accomplished with excellent yield and purity. Intriguingly, P() could be applied for selective absorption and recovery of Au³⁺ with >99% efficiency by exploiting the chemical recyclability of P().