Backbone-GovernedDesign of Polyrotaxanes: LinkingMacrocycle Dynamics to Functional Materials

Polyrotaxanes are mechanically interlocked systems where macrocycles thread through the polymer backbone and show unique topological mobility. They often exhibit structural adaptability and functional adjustability than traditional covalent polymers. However, the basic relationship between backbone structure, topological dynamics, and functional changes is not clear. This review sets up a backbone-governed framework. Flexible backbones promote macrocycle assembly and sliding-dominated dynamics, leading to stress redistribution, energy dissipation, and enhanced mechanical properties. In contrast, rigid π-conjugated backbones impose topological confinement, enabling localized dynamics, interchain decoupling, conformational stabilization, and improved optoelectronic performance. Based on these correlations, we establish hierarchical design principles linking backbone architecture, topological dynamic modes, molecular/network-level functions, and application-relevant performance. This backbone-centered perspective provides guidance for the rational and programmable design of mechanically interlocked functional materials.