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

Abstract

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.

Benzophenone derivatives as novel organosoluble visible light Type II photoinitiators for UV and LED photoinitiating systems

“…The BP-1/TEA system showed the highest decreasing in UV-vis intensity suggests this package has the faster photochemical reaction. [42] On the other hand, no significant decrease of BP-3/TEA package indicating an inefficiency for this system. Figure 6 displays the representative ESR spectra of selected BPs/TEA systems irradiated by UV lamp (wavelength, 250 < λ < 450 nm).…”

Synthesis and Structure-Activity Relationship of <i>N</i>-Substituted Carbazole Oxime Ester Photoinitiators

“…1 H NMR (400 MHz, chloroform-d) δ 8.48 (s, 1H), 8.16 (d, J = 1.9 Hz, 2H), 7.98 (d, J = 8.5 Hz, 2H), 7.69 (d, J = 8.4 Hz, 2H), 7.51 (dd, J = 8.7, 1.9 Hz, 2H), 7.43 (d, J = 8.6 Hz, 2H), 2.30 (s, 3H), 1.50 (s, 19H). 13 Synthesis of 4-(3,6-di-tert-butyl-9H-carbazol-9yl)benzaldehyde O-acryloyl oxime (Ph-N-CZ-4): Ph-N-CZ-4 was prepared via similar procedure described for Ph-N-CZ-1. Purification by column chromatography (petroleum ether/dichloromethane = 1:0.8) gave 0.151 g of the product as yellow solid powder.…”

“…Yield: 33.3%. 1 H NMR (400 MHz, chloroform-d) δ 8.55 (s, 1H), 8.17 Characterization: 1 H NMR and 13 C NMR spectra were obtained using a Bruker AVANCE III HD 400 MHz NMR spectrometer with CDCl3 or DMSO-d6 as the solvent. The high-resolution mass spectra were obtained using a Q-Tof-MS instrument from Bruker Daltonics.…”

“…Compared to traditional thermal polymerization, photopolymerization is efficient, environmentally friendly and easy to operate [10,12]. As a key component of photopolymerization system, photoinitiators play a very important role; they not only determine the polymerization rate but also affect the quality of final products [13,14].…”

Bis-chalcone derivatives derived from natural products as near-UV/visible light sensitive photoinitiators for 3D/4D printing

“…ultraviolet light, visible light or even infrared) [1][2][3][4][5][6]. With the advantages of reacting rapidly at room temperature while requiring a minimum of energy to be initiated, of being a relatively low cost polymerization technique allowing a perfect temporal and spatial control [7][8][9], free radical photopolymerization is still of crucial interest in both the academic and the industrial communities. Due to the severe limitations such as oxygen inhibition and light attenuation existing during the polymerization process due to shielding effects [10], the development of new high-performance photoinitiating systems that can work under near UV and/or visible light region, in environmentally friendly conditions and that are the less possible toxic are highly desirable.…”