Polymerizable Oxime Esters: An Efficient Photoinitiator with Low Migration Ability for 3D Printing to Fabricate Luminescent Devices

Abstract

The development of novel visible light photoinitiators (PIs) with low mobility for 3D printing will open up new applications for photopolymerization. In this work, a polymerizable visible light PI DCCA containing an oxime acryloyl ester structure was designed and synthesized. Its linear absorption has a maximum in the visible region (400-480 nm), overlapping well with the emission spectra of conventional blue light sources, and it can effectively induce acrylate polymerization under irradiation with a 450 nm LED lamp. In addition, migration of DCCA in the 3D printed samples is very low compared with DCCB, which has a similar structure but a phenyl moiety instead of the copolymerizable acrylate as the oxime ester group. The utility of DCCA in 3D printing was demonstrated by printing a 3D object with challenging geometric features with high resolution and accuracy.

3-Carboxylic Acid and Formyl-Derived Coumarins as Photoinitiators in Photo-Oxidation or Photo-Reduction Processes for Photopolymerization upon Visible Light: Photocomposite Synthesis and 3D Printing Applications

“…After stirring for another 30 min, the mixture was filtered, washed with water, pentane, and dried under vacuum (2.02 g, 86% yield). 1 H NMR (400 MHz, DMSO-d 6 ) δ 8.81 (d, J = 2.8 Hz, 1H), 8.51–8.33 (m, 2H), 7.59 (d, J = 9.1 Hz, 1H) Analyses were consistent with those previously reported in the literature [ 24 ].…”

“…Moreover, the Iod/NPG (1%/1% w / w ) couple weakly initiates the FRP (FC = 47%). This is ascribed to the formation of a charge transfer complex (CTC) between Iod and NPG [ 24 ] which is able to generate reactive species when it absorbs light. Clearly, the presence of Coumarin as photoinitiator is improving the performance of the photopolymerization processes.…”

Substituent effects on the photoinitiation ability of coumarin-based oxime-ester photoinitiators for free radical photopolymerization

“…Based on other elegant studies that have specifically reported coumarin-based oxime-esters as highly efficient visible light photoinitiators, containing phenyl [18,19,20] and methoxy groups [18] as substituents, in the present paper, we studied the coumarin-based oxime-ester structural effect 3 on the associated photoreactivity by introducing new substituents. More particularly the huge role of the decarboxylation reaction affected by the ester group is highlighted.…”

Novel chalcone derivatives with large conjugation structures as photosensitizers for versatile photopolymerization

“…The use of light-emitting diodes (LEDs) for photopolymerization applications have recently generated increased attention because of their efficient light output and low cost. [18][19][20] However, the development of new and efficient LEDsensitive PIs and PISs, such as oxime esters, [21][22][23][24][25] D-π-Acontaining photoacid generators, 16,18,26,27 and host-guest dye PIs, including ion-pair complexes, [28][29][30] is challenging.…”