Progress in Molecular Dynamics Simulations of Mechanically Interlocked Polymers

Mechanically interlocked polymers (MIPs) consist of molecular components connected by mechanical bonds, including slide ring junctions and rotaxane-based linkages that impose topological constraints, preventing separation without covalent scission and thus yielding distinct dynamical and mechanical properties compared with conventional polymers. Despite rapid synthetic progress, a quantitative account of the macroscopic response arising from sliding, threading, and knotting remains incomplete, since many governing variables act at mesoscopic scales that are difficult to measure. This Perspective reviews recent theoretical works on polyrotaxanes, polycatenanes, and molecular knots. Using theoretical approaches that span quantum chemistry, all-atom, and especially coarse-grained molecular dynamics (MD) simulations, we discuss how topological constraints govern conformational statistics, chain and network dynamics, relaxation behaviors, mechanical responses, and ring-sliding kinetics in MIMs and MIPs. Finally, we conclude by distilling best practices, recent advances, methodological standardization, and open challenges in MD studies of mechanically interlocked materials. We also outline clear guidelines and future opportunities for coupling theory-guided MD with targeted experiments to enable reliable validation and to establish design rules that inform synthesis, processing, and optimization.