Strong and Tough Supramolecular Covalent Adaptable Networks with Room-Temperature Closed-Loop Recyclability.

Development of closed-loop chemically recyclable plastics (CCRPs) that can be widely used in our daily life could be a fundamental solution to the global plastic waste crisis. Hence, it is of great significance to develop easy-to-recycle CCRPs that possess superior or comparable material properties to the commodity plastics. Here, we report a novel dual crosslinked CCRP, namely supramolecular covalent adaptable networks (supra-CANs), which not only display mechanical properties higher than the strong and tough commodity polycarbonate (PC), but also exhibit excellent solvent resistance as thermosets. The supra-CANs are constructed by introducing reversible noncovalent crosslinks into the dynamic covalent polymer networks, resulting in highly stiff and strong thermosets that also exhibit thermoplastic-like ductile and tough behaviors as well as reprocessability and rehealability. In great contrast, the analogues that don't have noncovalent crosslinks show elastomeric properties with significantly decreased mechanical strength. Importantly, the developed supra-CANs and CANs can be converted back into the initial monomers in high yields and purity at room temperature, even with additives, which enables the sustainable polymer-monomer-polymer circulation. This work provides new design principles for high-performance chemically recyclable CANs as sustainable substitutes for the conventional plastics. This article is protected by copyright. All rights reserved.