Engineering Energy Dissipation Pathway via Topological Design: Toward Tunable Macroscopic Mechanical Performances of Dynamic Polymer Networks

The incorporation of multiple supramolecular interactions as sacrificial bonds for energy dissipation has emerged as a powerful strategy to enhance the mechanical properties of elastomeric materials. However, precise control over energy dissipation pathways remains challenging, primarily due to the difficulty in selectively activating specific interactions on demand. Herein, we present an orthogonal self-assembly strategy that integrates host-guest recognition and metal-coordination to tailor energy dissipation mechanisms. We demonstrate that subtle modifications at the axial terminals of host-guest motifs dictate the formation of supramolecular polymer networks (SPNs) or mechanically interlocked networks (MINs), respectively. Upon external force, SPNs dissipate energy primarily through host‒guest dissociation, while coordination bonds remain intact. In contrast, in MINs, force transmission from the host to the axial stoppers following host‒guest dissociation leads to the rupture of metal-coordination bonds, enabling additional dissipate energy. This fundamental divergence in energy dissipation pathways results in superior mechanical performance in MIN-2, with higher strength (19.1 versus 14.5 MPa), toughness (57.7 versus 45.9 MJ m^-3), and puncture resistance compared to SPN-2. These findings highlight the potential of topological structure design in precisely tuning energy dissipation pathways, offering a robust and versatile strategy for developing high-performance supramolecular elastomers.