Monomeric and Polymeric Phenothiazine Photosensitizers for Photoinitiated Cationic Polymerization

Gomurashvili, Zaza; Crivello, James V.

doi:10.1021/ma0119272

Cited by 63 publications

(39 citation statements)

References 27 publications

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“…[71] Most of these studies were focused on cycloaliphatic epoxides which are the most utilized monomers because of their superior reactivity. The addition of a comonomer was shown to speed up the UVcuring process and to lead to a more complete polymerization, especially for aromatic diepoxides.…”

Section: Photoinitiated Cationic Polymerizationmentioning

confidence: 99%

Kinetic Study and New Applications of UV Radiation Curing

Decker

2002

Macromol. Rapid Commun.

620

448

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Highly crosslinked polymers can be readily synthesized by photoinitiated polymerization of multifunctional monomers or functionalized polymers. The reaction can be followed in situ by real‐time infrared (RT‐IR) spectroscopy, a technique that records conversion versus time curves in photosensitive resins undergoing ultrafast polymerization upon UV exposure. For acrylate‐based resins, UV‐curing proceeds with long kinetic chains (7700 mol/radical) in spite of the high initiation rate. RT‐IR spectroscopy proved very valuable in assessing the influence of various parameters, such as initiation efficiency, chemical structure of the telechelic oligomer, light intensity, inhibitory effect of oxygen, on polymerization kinetics. Interpenetrating polymer networks can be rapidly synthesized by means of UV irradiation of a mixture of difunctional acrylate and epoxy monomers in the presence of both radical and cationic‐type photoinitiators. The same UV technology can be applied to crosslink solid polymers at ambient temperature, which bear different types of reactive groups (acrylate and vinyl double bonds, epoxy ring). UV radiation curing has been successfully used to produce within seconds weathering resistant protective coatings, high‐resolution relief images, glass laminates and nanocomposites materials.Photoinitiated crosslinking polymerization.magnified imagePhotoinitiated crosslinking polymerization.

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Section: Photoinitiated Cationic Polymerizationmentioning

confidence: 99%

Kinetic Study and New Applications of UV Radiation Curing

Decker

2002

Macromol. Rapid Commun.

620

448

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“…Research has been reported by several groups including Crivello and co-workers, Yagci and co-workers, and Jacques Lalevée and co-workers. [19][20][21][22][23][24][25][26][27] Photolysis of onium salts is photosensitized by various monomeric and polymeric compounds containing the carbazole, triphenylamine and phenothiazine.…”

Section: -15mentioning

confidence: 99%

Carbazole-based compounds containing aldehyde and cyanoacetic acid: optical properties and applications in photopolymerization

et al. 2017

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Carbazole-based dyes containing aldehyde and cyanoacetic acid groups were synthesized through Sonogashira coupling and Knoevenagel reactions. These compounds included 6-((4-(diphenylamino)9-ethyl-9H-carbazol-3-yl)acrylic acid (TCN). Density functional theory (DFT) calculations revealed these structures to be coplanar-conjugated molecular and uniform in shape. The UV spectra showed three main absorption peaks from 240 nm to 400 nm, indicating p-p* and n-p* electron transitions. The calculated vertical singlet excitation energy was within the range of n-p*. This finding was confirmed based on the acceptor results in reduced highest occupied molecular orbital-lowest unoccupied molecular orbital gap by launching cyanoacetic acid. These functional compounds could be used as dyes/photosensitizers.

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“…The sensitizer, Rose Bengal (RB) and the initiator Nphenylglycine (NPG) (Kanto Chemical) were used as received. 3,3 -Carbonylbis(7-diethylaminocoumarin) (KC, Kodak) and diphenyliodonium hexafluorophosphate (DPI, AVOCADO Research Chemicals Ltd.) were used as PS and PI, respectively, to produce both cationic and radical species [22,23]. Visible photo-initiator, Irgacure 784 [bis(η 5 -cyclopentadienyl)bis[2,6-difluoro-3-(1H-pyrrol-1-y)]-titanium, Ciba-Geigy] to produce only radical species was also used.…”

Section: Composition Of Photo-initiator System and Recording Solutionmentioning

confidence: 99%

A novel process for holographic polymer dispersed liquid crystal system via simultaneous photo-polymerization and siloxane network formation

Cho

Kawakami

2007

Silicon Chem

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Formation of transmission holographic polymer dispersed liquid crystal gratings was studied for matrix components of trimethylolpropane triacrylate:trimethoxysilylmethyl methacrylate : 1-vinyl-2-pyrrolidone (reactive diluent) in the range from 80:10:10 wt% to 10:80:10 wt% and E7 as nematic liquid crystal under the irradiation with Nd-YAG laser (532 nm).The optimum concentration of E7 in the recording solution was 35 wt% (65 wt% of matrix components) in presence of small amounts of radical photo-initiator system (Rose Bengal 0.05 wt%, NPG 0.1 wt%). When the concentration of methacrylate in matrix components was low (<30%), gratings with apparently high diffraction efficiency could be fabricated both for trimethoxysilylmethyl methacrylate (cross-linkable by hydrolysis) and trimethylsilylmethyl methacrylate (non-cross-linkable by hydrolysis), although transiently high initial diffraction efficiency was observed by the non-equilibrium initial photo-polymerization of cross-linking components. Distinct difference was seen at higher concentration (>50 wt%) of the methacrylates. Contrary to that gratings with reasonably high and stable diffraction efficiency were successfully fabricated with trimethoxysilylmethyl methacrylate, gratings with only low diffraction efficiency were obtained for non-cross-linkable trimethylsilylmethyl methacrylate.With higher concentration of photo-sensitizer and photo-initiator (0.2 wt%; 1.0 wt%), and shorter irradiation time, gratings with high diffraction efficiency could be fabricated only for the photo-initiator system of 3,3 -carbonylbis(7-diethylaminocoumarin) and diphenyliodonium hexafluorophosphate with shorter induction period (∼174 s).Grating with diffraction efficiency of 72% was obtained with trimethoxysilylpropyl acrylate (80 wt% in the matrix component) and 35 wt% E7. By increasing the concentration of diphenyliodonium hexafluorophosphate to 2 wt%, diffraction efficiency increased to 85% and induction period was shortened to 129 s, and low volume shrinkage of 8% was attained via simultaneous radical cross-linking of trimethylolpropane triacrylate and siloxane network formation of trimethoxysilyl groups of trimethoxysilylmethyl acrylate by atmospheric moisture catalyzed by cationic species produced from the initiator system.In SEM morphology, although gratings formed with high concentration of trimethoxysilylpropyl acrylate had some cracks in polymer matrix, the largest grating spacing indicating the lowest volume shrinkage and very regular and well-defined gratings were observed.

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Monomeric and Polymeric Phenothiazine Photosensitizers for Photoinitiated Cationic Polymerization

Cited by 63 publications

References 27 publications

Kinetic Study and New Applications of UV Radiation Curing

Kinetic Study and New Applications of UV Radiation Curing

Carbazole-based compounds containing aldehyde and cyanoacetic acid: optical properties and applications in photopolymerization

A novel process for holographic polymer dispersed liquid crystal system via simultaneous photo-polymerization and siloxane network formation

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