Recent advances on pyrene-based photoinitiators of polymerization

Abstract

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Novel ketone derivative-based photoinitiating systems for free radical polymerization under mild conditions and 3D printing

“…Dissolution in a minimum of dichloromethane followed by addition of pentane precipitated a solid that was filtered off, washed several times with pentane and dried under vacuum (3.44 g, 91% yield). 1 dissolved in dichloromethane and the solution was filtered on a plug of SiO2 using dichloromethane as the eluent. The solvent was removed under reduced pressure.…”

“…Dissolution in a minimum of dichloromethane followed by addition of pentane precipitated a solid that was filtered off, washed several times with pentane and dried under vacuum (3.70 g, 95% yield). 1 During reaction, a precipitate formed. It was filtered off, washed several times with ethanol and dried under vacuum.…”

“…And usually, the photopolymerization reaction can be initiated by the type I (mono-component initiating system) or type II (bi-component or multiple-component initiating system) photoinitiators, of which the latter is especially versatile. [1][2][3][4][5] Thanks to these intrinsic advantages, such as fast polymerization kinetics, mild reaction conditions, environmentally friendly polymerization process, its economic aspect with less energy consumed, as well as an excellent spatial and temporal control, photopolymerization reactions have been widely studied and developed over the past decades. Now, the photopolymerization technique is attracting a widespread attention in both traditional and high-tech areas, including coatings, paints, inks, adhesives, microlithography, microelectronics, dentistry, and photocuring 3D-printing…to name just a few.…”

Free Radical Photopolymerization and 3D Printing Using Newly Developed Dyes: Indane-1,3-Dione and 1H-Cyclopentanaphthalene-1,3-Dione Derivatives as Photoinitiators in Three-Component Systems

“…Thus, a good solubility in resins is thus ensured. Indeed, the solubility of dyes within the photocurable resins also governs their ability to initiate a polymerization process and numerous examples of dyes with remarkable molar extinction coefficients, long-living excited state lifetime and appropriate redox properties could never initiate a polymerization due to their insolubility in resins [59][60][61][62][63][64][65][66][67][68]. Interestingly, the twenty-one dyes reported in this work are used for the first time in photoinitiating systems (PISs) combining a tertiary amine, ethyl dimethylaminobenzoate (EDB), as the electronic donor and an iodonium salt (acting as the electron acceptor) to promote the photopolymerization of benchmark acrylate monomers (see Scheme 2).…”

Recent Advances on Copper Complexes as Visible Light Photoinitiators and (Photo) Redox Initiators of Polymerization

“…Indeed, as shown in Figure 1 for a polystyrene latex with an average diameter of 112 nm containing fillers [21], light penetration can range from 600 µm at 400 nm up to 5 cm at 800 nm, enabling to revolutionize the scope of application of photopolymerization from coatings to the elaboration of thick samples [22]. At present, organic dyes used as visible light photosensitizers of polymerization have been extensively studied [23][24][25][26]. Interest for metal-free photoinitiators is notably motivated by the high costs of numerous metal precursors but also by the safety concerns raised by the use of transition metals.…”