Dual-responsive gas-releasing mechanophores

Mechanical damage is one of the prime reasons for lifetime shortening of polymeric materials in many applications. Currently, detection of mechanical damage relies on complicated equipment, and in many cases it is observed only after failure. Color changing mechanophores functionalities, which undergo selective mechanically induced chemical transformations, have been developed, but their visibility is limited to surface damage. Here, we describe the design and preparation of novel mechanophores that, undergo chemical transformations under mechanical stress to release CO, CO₂, COS and SO₂, all of which easily identified by portable gas detectors or even by human olfaction (for COS). These new mechanophores will allow the molecular level mechanical damage detection even inside a plastic material, not being limited to the surface.