Theory of flow-induced covalent polymer mechanochemistry in dilute solutions

Predicting polymer mechanochemistry in arbitrary flows is challenging due to the diversity of chain conformations, competition among stretched bonds, and flow heterogeneity. Here, we demonstrate that the vast diversity of polymer unravelling pathways must be accounted for, rather than considering an averaged chain conformation. We propose a model that describes both mechanophore activation and non-specific backbone scission, where the reaction rates depend solely on fluid kinematics. Validated with coarse-grained molecular dynamics simulations in complex flows, the model captures mechanochemistry onset, intact chain half-life, and non-specific scission.