Visible light induced photopolymerization: speeding up the rate of polymerization by using co-initiators in dye/amine photoinitiating systems

Grotzinger, Caroline; Burget, Dominique; Jacques, Patrice; Fouassier, Jean‐Pierre

doi:10.1016/s0032-3861(03)00286-6

Cited by 88 publications

(57 citation statements)

References 28 publications

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“…This leads to the formation of radical cation of dye and the radical anion of triazine. The latter species afterwards loses chloride anion to give the initiating radical (T  -), as was demonstrated for other triazine derivatives in presence of rose bengal [12]. Interesingly, the recorded cyclic voltammogram for T1 in acetonitrile ( At 510 nm (Scheme 7) it is possible to observe an increase of (T  -) signal, which clearly evidences the electron transfer process from sensitizer to triazine.…”

Section: Parallel-series Mechanismsupporting

confidence: 61%

“…This process leads to an increase of the free radical polymerization rate. Therefore, certain additives improve the polymerization efficiency, leading to the development of the so-called three-component photoinitiating systems [3][4][5][6][7][8][9][10][11][12]. Three-component initiator systems have consistently been found to be faster, more efficient, and more sensitive than their twocomponent counterparts [3].…”

Section: Radicals Of Photoinitiators Are Produced Through Several Folmentioning

confidence: 99%

“…Grotzinger and coworkers reported that when 1,3,5-triazine derivative accepts an electron, it produce 1,3,5-triazine radical anion which fragments to produce an active, initiating 1,3,5-triazynyl radical and a chloride anion [12]. Thus, triazine (T) accepts an electron from Cy * , and the product obtained undergoes a rapid unimolecular fragmentation reaction that limits back electron transfer.…”

Section: Kinetic Key Factors For Visible-light Activated Free Radicalmentioning

confidence: 99%

See 2 more Smart Citations

The Comparison of the Photoinitiating Ability of the Dyeing Photoinitiating Systems Acting via Photoreducible or Parallel Series Mechanism

Kabatc¹,

Jurek²

2012

Molecular Photochemistry - Various Aspects

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Section: Parallel-series Mechanismsupporting

confidence: 61%

Section: Radicals Of Photoinitiators Are Produced Through Several Folmentioning

confidence: 99%

Section: Kinetic Key Factors For Visible-light Activated Free Radicalmentioning

confidence: 99%

See 1 more Smart Citation

The Comparison of the Photoinitiating Ability of the Dyeing Photoinitiating Systems Acting via Photoreducible or Parallel Series Mechanism

Kabatc¹,

Jurek²

2012

Molecular Photochemistry - Various Aspects

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“…It has three main advantages: (i) the fundamental state of the PI is regenerated and can participate to a new cycle, (ii) supplementary initiating radicals are produced, (iii) potential terminating agents are consumed. Among the numerous PCIS redox additives reported in the literature, triazine derivatives (Tz) have been extensively used as electronacceptors in combination with amines, [12][13][14][15][16][17] thiols, [18] or borate salts. [18][19][20][21] They have been found to enhance final conversion and rate of polymerization by reacting with the semi-reduced form of the PI.…”

Section: Dedicated To Yusuf Yagci On the Occasion Of His 65th Annivermentioning

confidence: 99%

“…It has been reported that triazine A (TA) is not able to initiate acrylate photopolymerization when combined to several different dyes. [12,13] However, recent studies have proved that triazine derivatives are actually efficient to act as co-initiators, via a photoinduced electron transfer from the singlet state of pyrromethene derivatives. [15][16][17] Interestingly, isopropylthioxanthone (ITX) which is one of the most versatile photoinitiator for free radical photopolymerization (FRP) [23] has never been combined with triazine derivatives in a two-component photoinitiating system for FRP, although that such a combination has been studied for photoacid generation.…”

Section: Dedicated To Yusuf Yagci On the Occasion Of His 65th Annivermentioning

confidence: 99%

Triazine‐Based Type‐II Photoinitiating System for Free Radical Photopolymerization: Mechanism, Efficiency, and Modeling

Christmann

Allonas

Ley

et al. 2017

Macro Chemistry & Physics

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Isopropylthioxanthone, a versatile photoinitiator (PI) for free radical photopolymerization (FRP), is combined with a triazine derivative (Tz) in a Type-II photoinitiating system (PIS). Initiation ability of this system for acrylate photopolymerization is assessed using a diacrylate monomer. Involvement of a photoinduced electron transfer mechanism is demonstrated by time-resolved spectro scopic measurements. Further insights in this mechanism are obtained through the use of a photopolymerization kinetic model taking into account the main reaction steps from the absorption of photons to the formation of the polymer. Prediction ability of the model is also tested with different initial concentrations of PI and co-initiator, as well as a different Tz. This last experiment reveals the noticeable role of back electron transfer in the FRP mechanism of Type-II PIS. by the use of a photoinitiating system (PIS). It converts photons into chemical energy through the production of radicals capable of reacting with acrylic monomers to initiate macromolecular chains. Three main families of PIS have been developed, each with their own advantages and limitations. [2,[4][5][6][7][8][9] Type-I PIS rely on the photoinduced dissociation of the initiator to produce primary radicals. Despite a high quantum yield of radical production, typical bond dissociation energies require the use of UV lamps that are known to be harmful and to release ozone in the atmosphere. Therefore, Type-II PIS have been developed, which combine a photoinitiator (PI) able to absorb light and a co-initiator capable of reacting with the excited PI through hydrogen abstraction or electron transfer. Nevertheless, radical production is limited by the diffusion of the species into the viscous monomer medium and competition of the bimolecular reaction with PI deactivation pathways. In the case of hydrogen abstraction, hydrogenated PI radicals (PIH • , such as ketyl radicals) could also act as terminating agents and reduce final conversion. [10,11] Photocyclic initiating systems (PCIS) have then been developed in order to combine advantages of previous PIS, i.e.,

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Photopolymerization, Free Radical

Cai

Jessop

2004

Encyclopedia of Polymer Science and Technology

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Free‐radical photopolymerizations, which use light energy to initiate chain‐producing reactions, have many advantages over thermal polymerizations, including solvent‐free systems, spatial and temporal control of initiation, and high speed processing capabilities. This article provides an overview of the components, kinetics, and applications of free‐radical photopolymerization systems. Two general classes of photoinitiator systems (unimolecular and bimolecular) are discussed, as well as systems that have been developed to meet the demands of specific applications. (Meth)acrylates, which are the most widely used monomers in photopolymerization processes, and other commercially important free‐radical monomers, are described. The kinetic treatment of free‐radical photopolymerizations is outlined, with special emphasis on the photoinitiation step and its impact on the rate of polymerization expression. Kinetic modeling concerns in reaction systems containing monomers with more than one reactive group and in systems utilizing specialized polymerization methods are also considered. Finally, applications for free‐radical photopolymers in the automotive, electronic, medical, optical, graphic arts, flooring, and furniture industries are presented. This article provides the scientist or engineer with fundamental considerations of free‐radical photopolymerizations, along with references for more advanced topical research.

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Visible light induced photopolymerization: speeding up the rate of polymerization by using co-initiators in dye/amine photoinitiating systems

Cited by 88 publications

References 28 publications

The Comparison of the Photoinitiating Ability of the Dyeing Photoinitiating Systems Acting via Photoreducible or Parallel Series Mechanism

The Comparison of the Photoinitiating Ability of the Dyeing Photoinitiating Systems Acting via Photoreducible or Parallel Series Mechanism

Triazine‐Based Type‐II Photoinitiating System for Free Radical Photopolymerization: Mechanism, Efficiency, and Modeling

Photopolymerization, Free Radical

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