Substituent Effects on Photoinitiation Ability of Monoaminoanthraquinone‐Based Photoinitiating Systems for Free Radical Photopolymerization under LEDs

• Published in: Macromolecular rapid communications. Vol. 41; no. 18; pp. e2000166 - n/a
• Main Authors: Zhang, Jing, Lalevée, Jacques, Hill, Nicholas S., Kiehl, Jonathan, Zhu, Di, Cox, Nicholas, Langley, Julien, Stenzel, Martina H., Coote, Michelle L., Xiao, Pu
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 01.09.2020; Wiley-VCH Verlag
• Subjects: Absorption spectra; Additives; aminoanthraquinone; Anthraquinone; Anthraquinones; Chemical Sciences; Emission spectra; free radical photopolymerization; Free radicals; Irradiation; LEDs; Light emitting diodes; Monomers; Other; Photoinitiators; Photopolymerization; Triethanolamine; aminoanthraquinone; LEDs; photoinitiators; free radical photopolymerization
• ISSN: 1022-1336; 1521-3927
• DOI: 10.1002/marc.202000166

Three monoamino‐substituted anthraquinone derivatives (AAQs), that is, 1‐aminoanthraquinone (AAQ), 1‐(methylamino)anthraquinone (MAAQ), and 1‐(benzamido)anthraquinone (BAAQ), incorporated with various additives [e.g., triethanolamine (TEAOH) and phenacyl bromide (PhC(═O)CH2Br)] are investigated for their roles as photoinitiating systems of free radical photopolymerization of (meth)acrylate monomers upon the exposure to UV to green LEDs. The AAQs‐based photoinitiating systems, AAQ/TEAOH/PhC(═O)CH2Br and BAAQ/TEAOH/PhC(═O)CH2Br photoinitiators exhibit the highest efficiency for the free radical photopolymerization of DPGDA under the irradiation of blue LED and UV LED, respectively, which is consistent with the extent of overlap between their absorption spectra and the emission spectra of the LEDs. AAQ/TEAOH/PhC(═O)CH2Br photoinitiator can also initiate the free radical photopolymerization of different (meth)acrylate monomers, with an efficiency dependent on the chemical structures of these monomers. The variation in the amino groups of the monoaminoanthraquinone derivatives can strongly affect their light absorption properties and reactivities with additives (e.g., tertiary amines) to generate free radicals. Among all the investigated monoaminoanthraquinone‐based photoinitiating systems, the 1‐aminoanthraquinone‐based system exhibits the highest efficiency for the free radical photopolymerization under the irradiation of blue LED and green LED .