Flavones as natural photoinitiators for light mediated free-radical polymerization via light emitting diodes

In this work, we propose the use of flavones that can be derived from natural products as versatile high performance visible light photoinitiators initially with amino acid and later with iodonium salt and phosphino benzoic acid combinations for free-radical polymerization acrylates of thin specimen (25 mu m) and methacrylates thick specimen (1.4mm) upon illumination with near ultraviolet light or visible light utilizing light emitting diodes (LED)@385nm and LED@405nm. High polymerization initiating capabilities are found with different hydroxyflavones and high final conversions of the reactive function are obtained. Their application as materials for three-dimensional (3D) printing patterns is especially carried out for 1mm thick 3D printed photopolymers. A full description of the comprised photochemical mechanisms is additionally given. (c) 2020 Wiley Periodicals, Inc. J. Polym. Sci. 2020, 58, 254-262