A high performance, self-healing and closed-loop recycling composites based on salix through of imine and hydrogen bonds

The pollution caused by petroleum-based plastics to the ecological environment remains a major issue. The development of degradable polymers to replace petroleum-based plastics is of vital importance to environmental sustainability. This study prepared oxidized salix powder (OSP) by introducing aldehyde groups on the surface of salix by sodium periodate oxidation method, and prepared salix-based composite material (OSP/PI) by hot pressing with dynamic imine polymer (PI) as plastic alternative material. The integration of dynamic covalent imine linkages (-C N-) with hydrogen bonding facilitated robust interfacial interactions within the OSP/PI composite. The tensile strength of OSP/PI is 47.46 MPa and the Young’s modulus is 566.76 MPa. OSP/PI exhibits self-healing, reprocessing capabilities, thermal stability, water resistance and solvent resistance. OSP/PI can be chemically degraded and closed-loop recycled by diamine solution. OSP/PI completely degraded in natural soil within 5 months. The strategy of integrating the natural green attributes, high performance and recycling advantages of this biomass-based material provides a sustainable paradigm for the high-value utilization of Salix.