Perovskites as new radical photoinitiators for radical and cationic polymerizations

Four perovskites (LaTiO3, LaCrO3, La0.6Sr0.4MnO3 and MAPbl(3)) are proposed here as new photoinitiators (e.g., free radical generators) in combination with iodonium salt and optionally another additive (N-vinylcarbazole-NVK) to initiate both radical and cationic photopolymerization reactions. The proposed systems are efficient phenyl radical generators under polychromatic light sources such as a halogen lamp or a Xe-Hg lamp. The interest of this approach is the ability to work with very stable inorganic structures as photoinitiators. To the best of our knowledge, this is the first time that perovskites are incorporated in photoinitiating systems. Photochemical mechanisms will be proposed as sustained by electron spin resonance spin trapping (ESR-ST) experiments. (C) 2016 Elsevier Ltd. All rights reserved.