Symmetrically-substituted Thiazolo[5,4-d]thiazole derivatives as both photoinitiators and dyes for 3D printing under violet LED
Publication Name
Dyes and Pigments
Abstract
The outstanding photochemical properties of thiazolothiazole and its derivatives make them attractive as potential photoinitiators. Two homosubstituted thiazolo[5,4-d]thiazole derivatives, 2,5-di(furan-2-yl)thiazolo[5,4-d]thiazole and 2,5-di(thiophen-2-yl)thiazolo[5,4-d]thiazole, were investigated as photoinitiators for both the free radical and the cationic polymerization upon the light irradiation from LED@410 nm. In particular, steady-state photolysis, fluorescence quenching experiments, and electron paramagnetic resonance spin-trapping techniques were used to study their photochemical mechanisms in generating active species. When coupled with one or two additives, these thiazolothiazole-based photoinitiating systems showed effective photoinitiation abilities on both the free radical and the cationic photopolymerization. Specifically, 2,5-di(furan-2-yl)thiazolo[5,4-d]thiazole- and 2,5-di(thiophen-2-yl)thiazolo[5,4-d]thiazole-based photoinitiating systems were found to be of similar efficiency on the free radical photopolymerization of trimethylolpropane triacrylate and the dental resin (the blend of bisphenol A glycidyl methacrylate and triethylene glycol dimethacrylate) with minor shrinkage but presented different performance in cationic photopolymerization of 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate. Moreover, the curing depth of the samples and 3D printing capability were also investigated to determine their potential applications.
Open Access Status
This publication is not available as open access
Volume
206
Article Number
110638
Funding Number
CE 140100012
Funding Sponsor
Australian National Fabrication Facility