Covalent Adaptable Networks Mediated by Redox-Responsive Neighboring-Group-Participating Transalkylation

Covalent adaptable networks (CANs) typically require external catalysts to facilitate efficient crosslinker exchange, which can limit the reprocessability of the network due to leaching and degradation of the catalyst. In this study, the use of catalysts was avoided by employing a bicyclo[3.3.1]nonane (BCN) bis-alkyl halide crosslinker with selenium-based neighboring-group-participation (NGP) to enhance the rate of bond exchange. This thermally mediated C─N alkyl exchange and the associated flow behavior enabled the intrinsically ionic network (which possesses antimicrobial properties) to be both chemically recycled and repaired and reprocessed under mild conditions. Furthermore, the dynamic behavior of the network can be regulated by the reversible redox responsiveness of selenium atoms within the network. This novel type of NGP-based CAN therefore has the potential to enrich designs for catalyst-free dynamic networks with high performance and modulated dynamicity.