High Strength, Ultrahigh Adhesion, and Recyclable Biobased Nonisocyanate Polyurethane Adhesives Based on a Strategy Combining Rigid–Flexible and Highly Cross-Linked Structures

Adhesives play a vital role in traditional industries, aerospace, and battery assembly by facilitating the interfacial bonding of different materials to realize their potential applications. However, developing adhesives with simultaneous high strength, ultrahigh adhesion, resistance to extreme environments, and sustainability is important but also challenging. Therefore, inspired by the protective layer of soft-bodied arthropods, this work proposes a “rigid–flexible and highly cross-linked” strategy, with carbonated resveratrol as the rigid cross-linked structure to provide high-temperature resistance, biobased Priamine 1074 as the flexible long-chain segment to improve low-temperature resistance, and alicyclic diamines as the rigid short-chain segment to further optimize the adhesive strength through increased cross-linked density and intermolecular interaction. The resulting NIPU adhesives have a maximum strength of 82.0 MPa, a maximum adhesive strength of 22.0 MPa (steel as the substrate), and an outstanding resistance to extreme environments (−196 to 190 °C and organic solvents). The NIPU adhesives can be chemically recycled and reused, with a recovery efficiency exceeding 96.0%. Moreover, NIPUs can be used as an adhesive for cathode materials. The adhesive strength of NIPUs not only is superior to conventional PVDF adhesives but also allows for the recycling of cathode materials simply. This study provides a facile and effective “rigid–flexible and highly cross-linked” strategy for designing high-performance NIPU adhesives, which contributes to the development of the field of sustainable adhesive technology for extreme environments.