High-Performance, Recyclable Thermosets Enabled by Thiosemicarbazone Dynamic Bonds via Synergistic Dynamic Covalent...

Recyclable thermosets have emerged as promising candidates to mitigate plastic pollution, yet reconciling high performance with efficient recyclability remains challenging. Here, we report a high-performance, readily recyclable thermoset engineered through a synergistic dynamic covalent and supramolecular network. This design employs a single thiosemicarbazone (TSC) dynamic linkage to intrinsically unify dynamic covalent and noncovalent bonds within one chemical moiety, thereby overcoming conventional performance-recyclability trade-offs. The dual-network architecture endows the TSC-derived polymers (PTSCs) with exceptional thermal stability (glass transition temperature: 217°C), mechanical robustness (tensile strength: 127.1 MPa; elongation at break: 16.6%; Young's modulus: 2.1 GPa; toughness: 15.1 MJ m^-3), dimensional stability, and chemical resistance. Critically, the inherent reversibility of TSC bonds enables closed-loop recycling through in situ depolymerization and reconstruction over multiple cycles while retaining performance parity with virgin materials. This efficient recycling route confers genuine circularity, avoiding intermediate purification steps, minimizing solvent consumption, and streamlining the recycling workflow. Furthermore, PTSCs enable selective recovery from complex mixed plastic waste streams and carbon fiber composites without sophisticated separation processes. This work establishes a versatile molecular paradigm for designing readily recyclable thermosets with exceptional performance, advancing sustainable high-performance materials innovation.