Dynamic Synergy Effect between the Hydrogen Bond Network and Coordination Bond Network in Dual-Network Polyurethane Elastomers

How to effectively improve the strength and toughness of polymer elastomers is important for the expansion of their application fields. Construction of two distinct types of dynamic reversible bonds within elastomers represents an effective strategy for enhancing their mechanical properties. However, the interplay mechanisms between different dynamic reversible bonds have not been fully studied. Herein, we constructed both a hydrogen bond network and a metal coordination network in polyurethane (PU) elastomers. The introduction of both weak hydrogen bonds and strong metal coordination bonds can endow the elastomers with high tensile strength without the sacrifice of stretchability. This special phenomenon can be attributed to the dynamic synergistic mechanisms between the hydrogen bond network and coordination bond network. In short, the presence of strong coordination bonds can promote the orientation of local segments, while the recombination of weak hydrogen bonds can cause the relaxation of locally oriented segments.