Enhancing Mechanophore Activation through Polymer Crystallization

In the field of polymer mechanochemistry, the activation of mechanophores within linear polymers in the bulk state is often limited by low activation rates. Herein, we demonstrate that the crystallization of polymers can significantly enhance the activation of mechanophores. Employing rhodamine-containing poly(lactic acid) (PLA) and polycaprolactone (PCL) as representative examples, our study reveals that the micromechanical force generated by crystallization is more effective in activating mechanophores than the macroscopic mechanical force induced by compression and ultrasonication, which is particularly pronounced for polymers with low molecular weights. Furthermore, the activation of the mechanophore is found to be positively correlated with the degree of crystallinity and polymer molecular weight, whereas the chirality of polymers does not influence the activation. This study offers new insights into mechanochemical reactions induced by polymer crystallization and provides a novel approach to enhancing mechanochemical reactivity.