Even under low external force, a few macromolecules of a polymer have to be much more highly stressed and fractured first due to the inherent heterogeneous microstructure. When the materials keep on working under loading, as is often the case, the minor damages would add up, endangering the safety of use. Here we show an innovative solution based on mechanochemically initiated reversible cascading variation of metal-ligand complexations. Upon loading, crosslinking density of the proof-of-concept metallopolymer networks autonomously increases, and recovers after unloading. Meanwhile, the stress-induced tiny fracture precursors are blocked to grow and then restored. The entire processes reversibly proceed free of manual intervention and catalyst. The proposed molecular-level internal equilibrium prevention mechanisms fundamentally enhance durability of polymers in service.

即使在较低的外力作用下，由于固有的异质微观结构，聚合物的一些大分子也必须首先承受更高的应力和断裂。当材料在负载下继续工作时（通常），较小的损坏会加起来，危及使用的安全性。在这里，我们展示了一种基于金属化学配体络合的机械化学引发可逆级联变化的创新解决方案。加载后，概念验证的金属聚合物网络的交联密度自动增加，并在卸载后恢复。同时，应力诱发的微小裂缝前驱体被阻止生长然后恢复。整个过程可逆地进行，无需人工干预和催化剂。