Rapid activation of non-oriented mechanophores via shock loading and spallation

Mechanophores (MPs), stimuli-responsive molecules that respond chromatically to mechanochemical reactions, are important for understanding the coupling between mechanics and chemistry as well in engineering applications. However, atomic-level of their activation originates from gas phase studies or under simple linear elongation forces directly on polymer chains containing MPs. The effect many-body distortions, pervasive condensed-phase applications, is not understood. Therefore, we performed large-scale molecular dynamics (MD) simulations a poly(methyl methacrylate)-spiropyran copolymer dynamic mechanical loading studied MP various conditions dynamical compression tension during unloading. Detailed analysis all-atom MD trajectories shows blocks experience significant intramolecular distortion can significantly decrease barrier compared with when deformation rates slow relative relaxation time scales. We find reactivity MPs material states governed by effects torsions, whereas tension, reactions tensile stresses.