Novel Carbazole Skeleton-Based Photoinitiators for LED Polymerization and LED Projector 3D Printing

Assi Al Mousawi , Patxi Garra (1, 2) , Frederic Dumur (3) , Thanh-Tuan Bui (4) , Fabrice Goubard (4) , Joumana Toufaily (5) , Tayssir Hamieh (5) , Bernadette Graff (6) , Didier Gigmes (3) , Jean Pierre Fouassier (6) , Jacques Lalevee (7)

1 GRE - Laboratoire de Gestion des Risques et Environnement
2 IMITI - MIPS - Imagerie Microscopique et Traitement d’Images
3 ICR - Institut de Chimie Radicalaire
4 LPPI - Laboratoire de Physico-chimie des Polymères et des Interfaces
5 LU - Lebanese University [Beirut]
6 IS2M - Institut de Science des Matériaux de Mulhouse
7 IS2M - Institut de Science des Matériaux de Mulhouse

Radical chemistry is a very convenient way to produce polymer materials. Here, an application of a particular photoinduced radical chemistry is illustrated. Seven new carbazole derivatives Cd1-Cd7 are incorporated and proposed as high performance near-UV photoinitiators for both the free radical polymerization (FRP) of (meth)acrylates and the cationic polymerization (CP) of epoxides utilizing Light Emitting Diodes LEDs @405 nm. Excellent polymerization-initiating abilities are found and high final reactive function conversions are obtained. Interestingly, these new derivatives display much better near-UV polymerization-initiating abilities compared to a reference UV absorbing carbazole (CARET 9H-carbazole-9-ethanol) demonstrating that the new substituents have good ability to red shift the absorption of the proposed photoinitiators. All the more strikingly, in combination with iodonium salt, Cd1-Cd7 are likewise preferred as cationic photoinitiators over the notable photoinitiator bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide (BAPO) for mild irradiation conditions featuring their remarkable reactivity. In particular their utilization in the preparation of new cationic resins for LED projector 3D printing is envisioned. A full picture of the included photochemical mechanisms is given.

Keywords: 3D printing; cationic polymerization; cationic-polymerization; free radical polymerization; light emitting diodes (LEDs); photoinitiators; resins; systems; transfer radical polymerization; visible-light; cationic polymerization; free radical polymerization; light emitting diodes (LEDs); photoinitiators

Domains: Chemical Sciences

Assi Al Mousawi, Patxi Garra, Frederic Dumur, Thanh-Tuan Bui, Fabrice Goubard, et al.. Novel Carbazole Skeleton-Based Photoinitiators for LED Polymerization and LED Projector 3D Printing. Molecules, 2017, 22 (12), pp.2143. ⟨10.3390/molecules22122143⟩. ⟨hal-01774211⟩