Camphor-Based Nonisocyanate Polyurethane with Rapid Thermo-Healing and Closed-Loop Recyclability for Anticounterfeiting

Nonisocyanate polyurethanes (NIPUs), with their green synthesis routes, rich functional groups, and dynamic polyhydroxyurethane networks, provide a promising platform for durable, reprocessable, and optically responsive anticounterfeiting materials. However, creating biobased NIPUs that concurrently achieve recyclability, thermo-healing, and cluster-luminescent anticounterfeiting functionality remains highly challenging. Here, we report a biobased, thermo-healing, and recyclable NIPU material for anticounterfeiting purposes. Specifically, a camphoric acid-based cyclic carbonate, synthesized from biomass-derived camphoric acid and carbon dioxide (CO2), serves as the hard segment. For the soft segment, the biobased diamine Priamine 1074 is chosen, with triamine T-403 serving as the cross-linking agent. By adjusting the ratio of amine compounds, we successfully developed a series of thermo-healing, recyclable, and cluster-luminescent polyurethanes (PTPUs). In terms of mechanical properties, PTPU-20 achieves a maximum tensile strength of 11.3 MPa and a fracture elongation of 93%. Additionally, PTPU-20 exhibits intrinsic fluorescence, which arises from multiple n−π* transitions and hydrogen bonding between carbamate groups and free hydroxyl residues. As the temperature increases, its fluorescence emission peak undergoes a notable red shift, changing the color from green to yellow. Benefiting from dynamic exchange between carbamate bonds and free hydroxyl groups, PTPU-20 demonstrates exceptional thermo-healing and recyclability, with a thermo-healing efficiency exceeding 95%. After recycling, PTPUs also retain their fluorescent properties. This study provides a green and efficient synthetic strategy for sustainable NIPUs, highlighting their significant potential for applications in anticounterfeiting materials and information security.