Mechanoluminescent Polymers Based on Dithiomaleimide Dimer Mechanophores

Miaojiang Lv, Hang Shen（沈行）*, Zhengbiao Zhang（张正彪）*

State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, China

Macromolecules, 2025, 58, 7635

Abstract: Mechanoluminescent polymers based on mechanophores have gained significant interest due to their prospective applications in electronic skin, smart screens, and anticounterfeiting devices. Despite the progress made, there remains a demand for stable mechanophores that offer tunable reactivities. Herein, we report a novel dithiomaleimide (DTM) dimer mechanophore that undergoes a cycloreversion reaction to afford fluorescent DTM under mechanical force. Upon incorporation into poly(methyl acrylate) (PMA) and polyurethane, the DTM dimer shows mechanochemical reactivity in both solution and bulk states. Notably, the mechanophore with polymers directly attached to the four-membered ring displays enhanced reactivity, and the cis-configuration of the mechanophore is more beneficial to its activation than the trans-configuration. Additionally, the fluorescence intensity of the mechanophore is found to be positively correlated with the magnitude and duration of the applied mechanical force. The iterative activation of the mechanophores can be achieved by multiple compression cycles. Our study reveals the importance of structural design in enhancing the mechanochemical behavior of mechanophores and offers valuable insights for the development of mechanoresponsive materials with tunable reactivities.

Article information: https://doi.org/10.1021/acs.macromol.5c00462