Visible-Light-Driven Free Radical Polymerization and 3D Printing with Highly Efficient Carbazole-Substituted Aza-BODIPY Photoinitiators
Abstract
Photoinduced radical chemistry is pivotal for synthesizing polymeric materials under light irradiation. In this study, carbazole moieties were incorporated at distinct positions within the aza-boron-dipyrromethene (aza-BODIPY) scaffold, yielding three novel push–pull dyes that function as high-performance photoinitiators for the free radical polymerization of acrylates upon exposure to visible-light LED irradiation. When combined with iodonium salts or amines as co-initiators, these aza-BODIPY derivatives form efficient two-component photoinitiating systems that exhibit outstanding initiation performance. Notably, distinct polymerization kinetics were observed for two benchmark acrylate monomers. Through a combination of experimental investigations and theoretical calculations, a comprehensive photochemical mechanism has been elucidated. Furthermore, these newly developed carbazole-substituted aza-BODIPY-based photoinitiating systems enable the fabrication of high-resolution three-dimensional macroscale architectures via 3D printing. This work advances the fundamental understanding and practical application of visible-light-induced free radical polymerization.