Enhancing Mechanophore\nActivation through Polymer\nCrystallization

In the field of polymer mechanochemistry, the activation\nof mechanophores\nwithin linear polymers in the bulk state is often limited by low\nactivation rates. Herein, we demonstrate that the crystallization\nof polymers can significantly enhance the activation of mechanophores.\nEmploying rhodamine-containing poly(lactic acid) (PLA) and polycaprolactone\n(PCL) as representative examples, our study reveals that the micromechanical\nforce generated by crystallization is more effective in activating\nmechanophores than the macroscopic mechanical force induced by compression\nand ultrasonication, which is particularly pronounced for polymers\nwith low molecular weights. Furthermore, the activation of the mechanophore\nis found to be positively correlated with the degree of crystallinity\nand polymer molecular weight, whereas the chirality of polymers does\nnot influence the activation. This study offers new insights into\nmechanochemical reactions induced by polymer crystallization and provides\na novel approach to enhancing mechanochemical reactivity.