Tunable Mechanically Interlocked Semi-Crystalline Networks

High-performance polymers based on dynamic chemistry have been widely explored for multi-field advanced applications. However, noncovalent sacrifice bond mediated energy dissipation mechanism causes a trade-off between mechanical toughness and resilience. Herein, we achieved the synchronous boost of seemingly conflicting material properties including mechanical robustness, toughness and elasticity via the incorporation of mechanical chemistry into traditional semi-crystalline networks. Detailed rheological tests and all-atom molecular dynamics simulation reveal that the excellent mechanical robustness and toughness are attributed to the dissociation of crystalline domains threading through the sieve-shape macrocycles. Reversible nano-crystalline domains and ring-sliding effect accelerated segment motion efficiently reduce energy dissipation to achieve instantaneous resilience. Moreover, the model polymers demonstrate that the multiple dynamic components endow the resulting polymer with excellent reprocessability under mild conditions. This mechanically interlocked semi-crystalline polymer exhibits potential application as thermal/photo actuator. This work deeply reveals the synergic effects of mechanically interlocked sites and tunable crystalline domains, thus providing a reliable guide for comprehensive improvement of material performance.