Thermomechanical activation achieving orthogonal working/healing conditions of nanostructured tri-block copolymer thermosets

Conventional thermosets, despite their technological significance in today's materials economy, present a modern sustainability challenge because of their lack of end-of-life options for recyclability or reprocessability. Emerging covalent adaptable networks (CANs) offer sustainable alternatives to permanently crosslinked materials, but ideal orthogonal working/reprocessing conditions are hardly achievable by the current thermochemical activation mechanism. Here we report a CAN system of additive/catalyst-free, fully reprocessable, crosslinked, tri-block copolymer (tri-BCP) thermoplastic elastomer networks based on acid-anhydride bond exchange operated on a thermomechanical activation mechanism. The unique functionality of the tri-BCP architecture enables self-assembly into inter linked, hexagonally packed cylinder nanostructures that preclude any productive inter-cylinder bond exchange (and, thus, creep) without cooperative thermal and mechanical (heating and compression) processing conditions.

Automated summary

This study presents a novel tri-block copolymer thermoplastic elastomer network based on acid-anhydride bond exchange operated on a thermomechanical activation mechanism. The system is free of additives/catalysts and fully reprocessable, and its unique architecture allows self-assembly into structured nanostructures that prevent unproductive bond exchange.