Force-Reversible and Energetic Indole-Mg-Indole Cation-π Interaction for Designing Toughened and Multifunctional High-Performance Thermosets

Non-covalent crosslinking has provided versatile and affordable solutions for the design of tough soft polymer materials, but it is not applied in stiff high-performance thermosets. Here, the authors report a supramolecular approach for the design of tough high-performance thermosets by using noncovalent sandwich-structural indole-Mg-indole complexes that act as the force-reversible and energetic crosslinking points, evading the inherent trade-off between mechanical strength and ductility for high-performance thermosets. Compared to traditional epoxy polymer materials, the indole-Mg-indole crosslinks of the network enables synchronously enhancement of mechanical strength and ductility owing to the increased interaction-energy and efficient dissociation and reassociation behaviors given by the dynamic indole-Mg-indole complexes, which is quite challenging to achieve by conventional chemical methods. In addition, local manipulation of crosslinking confers the resulting thermosets with multiple fast stimuli-responsive functions, such as recyclability, healability, and adhesion.

Automated summary

This study presents a supramolecular approach using noncovalent sandwich-structural complexes to design tough high-performance thermosets, overcoming the inherent trade-off between mechanical strength and ductility for high-performance thermosets. The resulting materials exhibit multiple fast stimuli-responsive functions, such as recyclability, healability, and adhesion.