Recyclable nacre-inspired elastomer via dynamic supramolecular nanosheets

Artificial nacre-like composites based on well-aligned nanosheets and interlaminated polymers combine various advantages such as toughness, stiffness and solvent/gas barrier, but their difficulty on recycling causes waste and pollution. To address this issue, we develop nacre-like polyurethane composites through Diels-Alder crosslinking reaction between the polymer chains and Janus nanoparticles. The Janus nanoparticles can in-situ assemble into oriented supramolecular layered-nanosheets, and the interfacial Diels-Alder (DA) bonds connect the rigid layered-nanosheets and the flexible chain backbones of polyurethane to form a nacre-like hybrid network. Such network not only improves the mechanical properties, water tolerance and gas barrier performances of the composites, but also endows the composites with outstanding recycling ability. Therefore, this work provides a feasible strategy for the development of recyclable nacre-like composites with high-performance.