Design of keto-coumarin based photoinitiator for Free Radical Photopolymerization: Towards 3D printing and photocomposites applications

In this article, ten organic dyes based on keto-coumarin (KC) derivatives (MeO-Coum1, MeO-Coum10) have been synthesized and characterized as high performance photoinitiators for the Free Radical Photopolymerization (FRP) of acrylates upon visible light exposure using a Light emitting diode (LED) @405 nm. The addition Iodonium salt (Iod), amine [ethyl dimethylaminobenzoate (EDB) or N-phenylglycine (NPG)] Iod/NPG couple in photocurable resins carried out order to prove their influences improvement photoinitiating abilities keto-coumarins. different showed very ability initiate by introduction these additives, Two Three-component systems MeO-Coum/Iod (0.1% 0.4%/1% w/w) MeO-Coum/Iod/NPG 0.4%/1%/1% w/w/w) respectively. fact, tested applications. For example: direct laser write generate 3D patterns nm, photocomposite synthesis glass fibers. To characterize initiation explain reaction mechanisms photoinitiation step, several techniques used, such UV–visible spectroscopy steady state photolysis, fluorescence emission, RT-FTIR cyclic voltammetry experiments.