Pressure-Sensitive Chromogenic Polyesters

Cyano-OPV moieties were covalently incorporated into a PETG backbone to create ductile amorphous polymers which change their PL and absorption color as a function of deformation. The cyano-OPV concentration was systematically varied, and the composition was related to the material's optical response. This approach afforded PETG/dye copolymers which upon annealing display characteristics of aggregated dye molecules. The materials exhibit a significant color change upon compression, consistent with disassembly of the dye aggregates. This mechanochromic response is irreversible and can be detected by the unassisted eye.