LAUSR

Covalent adaptable networks (CANs) have the potential to replace classical thermosets, as their unique dynamic-covalent bonds enable reprocessing and recycling of crosslinked polymers. A challenge for CANs remains their creep susceptibility, which hampers their application. Herein, we demonstrate an efficient strategy to enhance creep resistance of CANs via metal coordination to dynamic-covalent imine groups. Crucially, the coordination bonds not only form additional crosslinks inside the network, but also directly affect the imine exchange properties due to metal coordination to the imines. The result of this dual effect is that various material properties, e.g., glass transition temperature (Tg ) and elastic modulus (G') were enhanced. The robustness of metal coordination was demonstrated by varying metal ion, counter anion, and coordinating imine ligand. All variations in metal or anion significantly enhanced the material properties. The Tg and G' of the CANs could be correlated to the coordination bond strength, offering a tunable handle by which choice of metal can steer the material properties. Additionally, we observed large differences in Tg and G' for materials with different anions, which were mostly linked to the anion size. This serves as a reminder that for coordination chemistry in the bulk, not only the metal ion is to be considered, but also the accompanying anion. Finally, the reinforcing effect of metal coordination proved insensitive to the metal-ligand ratio, which furthers add to the robustness of our approach for tuning material properties. This article is protected by copyright. All rights reserved.