Wavelength-Tunable Light-Induced Polymerization of Cyanoacrylates Using Photogenerated Amines

Cyanoacrylate photopolymerization has already been described, but it generally requires the use of organometallic photoinitiators and highly reactive monomers, which often leads to photoinitiator-monomer mixtures with limited stability. In this work we report a method to tackle these limitations, which relies on the use of amines bearing photoremovable protecting groups as light-responsive nucleophilic cyanoacrylate initiators. By exploiting the versatility of amine photorelease strategies, we have developed a series of all-organic initiators that (a) enable fast, on demand photocuring of commercial formulations of various cyanoacrylates, including less reactive, biologically relevant long alkyl chain monomers; (b) show wavelength tunability along the UV-vis spectrum and good thermal stability in the dark; and (c) lead to polymeric materials with excellent adhesive behavior. Because of this combination of properties, photogenerated amines appear as ideal candidates to bring cyanoacrylate photopolymerization into real application, especially in the biomedical field.