Precision synthesis and mechanochemical structure–reactivity relationships of mechanophore-bearing polymers with diverse conformations

While polymer conformation is known to influence mechanochemical reactivity, a platform that enables systematic evaluation of the conformational effects on mechanochemical transduction, including both chain scission and nonscissile mechanophore activation, has been lacking. Here, we synthesize a series of polymers bearing multiple nonscissile mechanophores, with controlled degrees of polymerization and systematic sidechain variation, yielding conformations spanning globule-like, coil, and rod-like structures. Ultrasound-induced chain scission reveals that the chain scission rate increases with sidechain mass across all conformations. Mechanophore activation further indicates that backbone flexibility strongly influences the extent of polymer uncoiling and the efficiency of force transduction. Molecular dynamics simulations show that steric hindrance from the sidechains influences backbone flexibility, thereby controlling polymer uncoiling and force transduction. These findings provide insights into the fundamental factors governing polymer mechanochemistry and open the door to developing stress-responsive materials with tunable responses. Precise control over mechanochemical reactivity is important for the development of force-responsive polymers and mechanically triggered drug-release systems, but remains challenging. Here, the authors show that varying polymer side chains alters polymer conformation and thereby modulates mechanochemical reactivity.