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Jacques Lalevee - One of the best experts on this subject based on the ideXlab platform.
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different nir dye scaffolds for Polymerization Reactions under nir light
Polymer Chemistry, 2019Co-Authors: Didier Gigmes, Frédéric Dumur, Jean-pierre Fouassier, Audeheloise Bonardi, Celine Dietlin, Guillaume Noirbent, Fabrice Bonardi, Jacques LaleveeAbstract:In this article, near-infrared dyes of different structures have been investigated as new photoinitiators/photosensitizers for the free radical Polymerization (FRP) of methacrylates upon Near InfraRed (NIR) light exposure using a laser diode @785 nm, @940 nm and @1064 nm. Interestingly, the use of squaraine, squarylium, boron-pyrromethene and porphyrin derivatives as efficient photoinitiators is clearly highlighted. These dyes are used in combination with an iodonium salt and a phosphine. Additionally, a thermal initiator can be added to the resin to take advantage of the photothermal effect, i.e., to the heat release during the Polymerization process, so that Polymerization kinetics could be greatly improved compared to the pure photochemical mode. These dyes can be proposed as alternatives to the well-established cyanine dyes, more commonly used for the photoPolymerization of (meth)acrylates under NIR light.
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photocatalysts in Polymerization Reactions
Chemcatchem, 2016Co-Authors: Nicolas Zivic, Didier Gigmes, Frédéric Dumur, Jean-pierre Fouassier, Mariem Bouzratizerelli, Anthony Kermagoret, Jacques LaleveeAbstract:A short review of the role of photocatalysts in photoPolymerization Reactions is presented. A special emphasis is placed on photoredox catalysts leading to i) high-performance initiating systems for Polymerization upon low light intensity for the use of light emitting diodes (LEDs) and/or visible light and ii) controlled radical photoPolymerization (CRP2) processes with formation/reactivation of dormant species triggered by light.
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naphthalimide phthalimide derivative based photoinitiating systems for Polymerization Reactions under blue lights
Journal of Polymer Science Part A, 2015Co-Authors: Pu Xiao, Bernadette Graff, Didier Gigmes, Frédéric Dumur, Jean-pierre Fouassier, Jing Zhang, Jacques LaleveeAbstract:Naphthalimide-phthalimide derivatives (NDPDs) have been synthesized and combined with an iodonium salt, N-vinylcarbazole, amine or 2,4,6-tris(trichloromethyl)-1,3,5-triazine to produce reactive species (i.e., radicals and cations). These generated reactive species are capable of initiating the cationic Polymerization of epoxides and/or the radical Polymerization of acrylates upon exposure to very soft polychromatic visible lights or blue lights. Compared with the well-known camphorquinone based systems used as references, the novel NDPD based combinations employed here demonstrate clearly higher efficiencies for the cationic Polymerization of epoxides under air as well as the radical Polymerization of acrylates. Remarkably, one of the NDPDs (i.e., NDPD2) based systems is characterized by an outstanding reactivity. The structure/reactivity/efficiency relationships of the investigated NDPDs were studied by fluorescence, cyclic voltammetry, laser flash photolysis, electron spin resonance spin trapping, and steady state photolysis techniques. The key parameters for their reactivity are provided. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 665–674
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Naphthalimide‐phthalimide derivative based photoinitiating systems for Polymerization Reactions under blue lights
Journal of Polymer Science Part A, 2014Co-Authors: Pu Xiao, Bernadette Graff, Didier Gigmes, Frédéric Dumur, Jean-pierre Fouassier, Jing Zhang, Jacques LaleveeAbstract:Naphthalimide-phthalimide derivatives (NDPDs) have been synthesized and combined with an iodonium salt, N-vinylcarbazole, amine or 2,4,6-tris(trichloromethyl)-1,3,5-triazine to produce reactive species (i.e., radicals and cations). These generated reactive species are capable of initiating the cationic Polymerization of epoxides and/or the radical Polymerization of acrylates upon exposure to very soft polychromatic visible lights or blue lights. Compared with the well-known camphorquinone based systems used as references, the novel NDPD based combinations employed here demonstrate clearly higher efficiencies for the cationic Polymerization of epoxides under air as well as the radical Polymerization of acrylates. Remarkably, one of the NDPDs (i.e., NDPD2) based systems is characterized by an outstanding reactivity. The structure/reactivity/efficiency relationships of the investigated NDPDs were studied by fluorescence, cyclic voltammetry, laser flash photolysis, electron spin resonance spin trapping, and steady state photolysis techniques. The key parameters for their reactivity are provided. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 665–674
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new chromone based photoinitiators for Polymerization Reactions under visible light
Polymer Chemistry, 2013Co-Authors: Mohamadali Tehfe, Bernadette Graff, Didier Gigmes, Frédéric Dumur, Jean-pierre Fouassier, Pu Xiao, Fabrice Morletsavary, Jacques LaleveeAbstract:Novel photoinitiators derived from a chromone structure are proposed for the free radical Polymerization of acrylates and the free radical promoted cationic Polymerization of epoxides upon exposure to a 457 nm laser diode and even under soft irradiation conditions (blue LED bulb at 462 nm and halogen lamp). Good Polymerization profiles are obtained. These original dyes exhibit a push–pull molecular character as revealed by MO calculations. The initiation mechanisms are analyzed through ESR, fluorescence and laser flash photolysis experiments.
Jean-pierre Fouassier - One of the best experts on this subject based on the ideXlab platform.
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different nir dye scaffolds for Polymerization Reactions under nir light
Polymer Chemistry, 2019Co-Authors: Didier Gigmes, Frédéric Dumur, Jean-pierre Fouassier, Audeheloise Bonardi, Celine Dietlin, Guillaume Noirbent, Fabrice Bonardi, Jacques LaleveeAbstract:In this article, near-infrared dyes of different structures have been investigated as new photoinitiators/photosensitizers for the free radical Polymerization (FRP) of methacrylates upon Near InfraRed (NIR) light exposure using a laser diode @785 nm, @940 nm and @1064 nm. Interestingly, the use of squaraine, squarylium, boron-pyrromethene and porphyrin derivatives as efficient photoinitiators is clearly highlighted. These dyes are used in combination with an iodonium salt and a phosphine. Additionally, a thermal initiator can be added to the resin to take advantage of the photothermal effect, i.e., to the heat release during the Polymerization process, so that Polymerization kinetics could be greatly improved compared to the pure photochemical mode. These dyes can be proposed as alternatives to the well-established cyanine dyes, more commonly used for the photoPolymerization of (meth)acrylates under NIR light.
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photoinduced thermal Polymerization Reactions
Macromolecules, 2018Co-Authors: Audeheloise Bonardi, Frédéric Dumur, Jean-pierre Fouassier, Fabrice Morletsavary, Fabien Bonardi, Celine Dietlin, Guillaume Noirbent, Trevor M Grant, Benoit H LessardAbstract:The combination of thermally induced and photoinduced free radical Polymerization of (meth)acrylic monomers has only been scarcely presented in the literature. In this study, a two-component system with a near-infrared (NIR) dye combined with a thermal initiator is presented. The dye acts as a very efficient heat generator (heater) upon irradiation with NIR light. Several thermal initiators are presented such as an alkoxyamine (e.g., BlocBuilder-MA), azo derivatives, and (hydro)peroxides. The heat delivered by the dye dissociates the thermal initiator, which initiates the free radical Polymerization of (meth)acrylates. Several types of heat generators are presented such as borate-based dyes and a silicon phthalocyanine derivative. For the first time, the effects of the NIR heater concentration, light intensity, and monomer structure on the heat released are studied using thermal imaging studies. NIR light curing is challenging but offers significant advantages: it is safer than shorter wavelength, and it ...
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photocatalysts in Polymerization Reactions
Chemcatchem, 2016Co-Authors: Nicolas Zivic, Didier Gigmes, Frédéric Dumur, Jean-pierre Fouassier, Mariem Bouzratizerelli, Anthony Kermagoret, Jacques LaleveeAbstract:A short review of the role of photocatalysts in photoPolymerization Reactions is presented. A special emphasis is placed on photoredox catalysts leading to i) high-performance initiating systems for Polymerization upon low light intensity for the use of light emitting diodes (LEDs) and/or visible light and ii) controlled radical photoPolymerization (CRP2) processes with formation/reactivation of dormant species triggered by light.
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naphthalimide phthalimide derivative based photoinitiating systems for Polymerization Reactions under blue lights
Journal of Polymer Science Part A, 2015Co-Authors: Pu Xiao, Bernadette Graff, Didier Gigmes, Frédéric Dumur, Jean-pierre Fouassier, Jing Zhang, Jacques LaleveeAbstract:Naphthalimide-phthalimide derivatives (NDPDs) have been synthesized and combined with an iodonium salt, N-vinylcarbazole, amine or 2,4,6-tris(trichloromethyl)-1,3,5-triazine to produce reactive species (i.e., radicals and cations). These generated reactive species are capable of initiating the cationic Polymerization of epoxides and/or the radical Polymerization of acrylates upon exposure to very soft polychromatic visible lights or blue lights. Compared with the well-known camphorquinone based systems used as references, the novel NDPD based combinations employed here demonstrate clearly higher efficiencies for the cationic Polymerization of epoxides under air as well as the radical Polymerization of acrylates. Remarkably, one of the NDPDs (i.e., NDPD2) based systems is characterized by an outstanding reactivity. The structure/reactivity/efficiency relationships of the investigated NDPDs were studied by fluorescence, cyclic voltammetry, laser flash photolysis, electron spin resonance spin trapping, and steady state photolysis techniques. The key parameters for their reactivity are provided. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 665–674
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Naphthalimide‐phthalimide derivative based photoinitiating systems for Polymerization Reactions under blue lights
Journal of Polymer Science Part A, 2014Co-Authors: Pu Xiao, Bernadette Graff, Didier Gigmes, Frédéric Dumur, Jean-pierre Fouassier, Jing Zhang, Jacques LaleveeAbstract:Naphthalimide-phthalimide derivatives (NDPDs) have been synthesized and combined with an iodonium salt, N-vinylcarbazole, amine or 2,4,6-tris(trichloromethyl)-1,3,5-triazine to produce reactive species (i.e., radicals and cations). These generated reactive species are capable of initiating the cationic Polymerization of epoxides and/or the radical Polymerization of acrylates upon exposure to very soft polychromatic visible lights or blue lights. Compared with the well-known camphorquinone based systems used as references, the novel NDPD based combinations employed here demonstrate clearly higher efficiencies for the cationic Polymerization of epoxides under air as well as the radical Polymerization of acrylates. Remarkably, one of the NDPDs (i.e., NDPD2) based systems is characterized by an outstanding reactivity. The structure/reactivity/efficiency relationships of the investigated NDPDs were studied by fluorescence, cyclic voltammetry, laser flash photolysis, electron spin resonance spin trapping, and steady state photolysis techniques. The key parameters for their reactivity are provided. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 665–674
Frédéric Dumur - One of the best experts on this subject based on the ideXlab platform.
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different nir dye scaffolds for Polymerization Reactions under nir light
Polymer Chemistry, 2019Co-Authors: Didier Gigmes, Frédéric Dumur, Jean-pierre Fouassier, Audeheloise Bonardi, Celine Dietlin, Guillaume Noirbent, Fabrice Bonardi, Jacques LaleveeAbstract:In this article, near-infrared dyes of different structures have been investigated as new photoinitiators/photosensitizers for the free radical Polymerization (FRP) of methacrylates upon Near InfraRed (NIR) light exposure using a laser diode @785 nm, @940 nm and @1064 nm. Interestingly, the use of squaraine, squarylium, boron-pyrromethene and porphyrin derivatives as efficient photoinitiators is clearly highlighted. These dyes are used in combination with an iodonium salt and a phosphine. Additionally, a thermal initiator can be added to the resin to take advantage of the photothermal effect, i.e., to the heat release during the Polymerization process, so that Polymerization kinetics could be greatly improved compared to the pure photochemical mode. These dyes can be proposed as alternatives to the well-established cyanine dyes, more commonly used for the photoPolymerization of (meth)acrylates under NIR light.
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simultaneous initiation of radical and cationic Polymerization Reactions using the g1 copper complex as photoredox catalyst applications of free radical cationic hybrid photoPolymerization in the composites and 3d printing fields
Progress in Organic Coatings, 2019Co-Authors: Frédéric Dumur, Fabrice Morletsavary, Celine Dietlin, Haifaa Mokbel, D Anderson, R Plenderleith, Didier GigmesAbstract:Abstract This investigation presents the use of a photoredox catalyst "G1" as a photoinitiating system for free radical/cationic hybrid Polymerization under mild irradiation conditions. The G1 system (G1/iodonium salt/N-vinylcarbazole), can simultaneously initiate the free radical and cationic Polymerization Reactions upon exposure to a visible (405 nm) light from a Light Emitting Diode (LED) source. The multicomponent G1 system is able to simultaneously generate radical and cationic species through a catalytic photoredox process. The curing of thin samples (25 μm), thick samples (1.4 mm) as well as the manufacture of hybrid system/glass fibers composites (˜2 to 4 mm thickness) was realized and the influence of the ratio of cationic/radical monomer blends on the Polymerization kinetics was studied. The use of G1 in visible light photoinitiating system for the access to composites and 3D printing experiments was particularly outlined. G1 was also shown to have low levels of migration from the cured materials. When compared to reference materials ("F1", a similar copper complex and an anthracene derivative, dibutoxy anthracene), G1 showed better Polymerization efficiency. The initiation efficiency was investigated through the real-time Fourier transform infrared (RT-FTIR) spectroscopy and optical pyrometry. Dynamical Mechanical Analysis has been used to determine the glass temperature transition of the cured hybrid system as a complementary technique.
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photoinduced thermal Polymerization Reactions
Macromolecules, 2018Co-Authors: Audeheloise Bonardi, Frédéric Dumur, Jean-pierre Fouassier, Fabrice Morletsavary, Fabien Bonardi, Celine Dietlin, Guillaume Noirbent, Trevor M Grant, Benoit H LessardAbstract:The combination of thermally induced and photoinduced free radical Polymerization of (meth)acrylic monomers has only been scarcely presented in the literature. In this study, a two-component system with a near-infrared (NIR) dye combined with a thermal initiator is presented. The dye acts as a very efficient heat generator (heater) upon irradiation with NIR light. Several thermal initiators are presented such as an alkoxyamine (e.g., BlocBuilder-MA), azo derivatives, and (hydro)peroxides. The heat delivered by the dye dissociates the thermal initiator, which initiates the free radical Polymerization of (meth)acrylates. Several types of heat generators are presented such as borate-based dyes and a silicon phthalocyanine derivative. For the first time, the effects of the NIR heater concentration, light intensity, and monomer structure on the heat released are studied using thermal imaging studies. NIR light curing is challenging but offers significant advantages: it is safer than shorter wavelength, and it ...
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photocatalysts in Polymerization Reactions
Chemcatchem, 2016Co-Authors: Nicolas Zivic, Didier Gigmes, Frédéric Dumur, Jean-pierre Fouassier, Mariem Bouzratizerelli, Anthony Kermagoret, Jacques LaleveeAbstract:A short review of the role of photocatalysts in photoPolymerization Reactions is presented. A special emphasis is placed on photoredox catalysts leading to i) high-performance initiating systems for Polymerization upon low light intensity for the use of light emitting diodes (LEDs) and/or visible light and ii) controlled radical photoPolymerization (CRP2) processes with formation/reactivation of dormant species triggered by light.
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naphthalimide phthalimide derivative based photoinitiating systems for Polymerization Reactions under blue lights
Journal of Polymer Science Part A, 2015Co-Authors: Pu Xiao, Bernadette Graff, Didier Gigmes, Frédéric Dumur, Jean-pierre Fouassier, Jing Zhang, Jacques LaleveeAbstract:Naphthalimide-phthalimide derivatives (NDPDs) have been synthesized and combined with an iodonium salt, N-vinylcarbazole, amine or 2,4,6-tris(trichloromethyl)-1,3,5-triazine to produce reactive species (i.e., radicals and cations). These generated reactive species are capable of initiating the cationic Polymerization of epoxides and/or the radical Polymerization of acrylates upon exposure to very soft polychromatic visible lights or blue lights. Compared with the well-known camphorquinone based systems used as references, the novel NDPD based combinations employed here demonstrate clearly higher efficiencies for the cationic Polymerization of epoxides under air as well as the radical Polymerization of acrylates. Remarkably, one of the NDPDs (i.e., NDPD2) based systems is characterized by an outstanding reactivity. The structure/reactivity/efficiency relationships of the investigated NDPDs were studied by fluorescence, cyclic voltammetry, laser flash photolysis, electron spin resonance spin trapping, and steady state photolysis techniques. The key parameters for their reactivity are provided. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 665–674
Didier Gigmes - One of the best experts on this subject based on the ideXlab platform.
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different nir dye scaffolds for Polymerization Reactions under nir light
Polymer Chemistry, 2019Co-Authors: Didier Gigmes, Frédéric Dumur, Jean-pierre Fouassier, Audeheloise Bonardi, Celine Dietlin, Guillaume Noirbent, Fabrice Bonardi, Jacques LaleveeAbstract:In this article, near-infrared dyes of different structures have been investigated as new photoinitiators/photosensitizers for the free radical Polymerization (FRP) of methacrylates upon Near InfraRed (NIR) light exposure using a laser diode @785 nm, @940 nm and @1064 nm. Interestingly, the use of squaraine, squarylium, boron-pyrromethene and porphyrin derivatives as efficient photoinitiators is clearly highlighted. These dyes are used in combination with an iodonium salt and a phosphine. Additionally, a thermal initiator can be added to the resin to take advantage of the photothermal effect, i.e., to the heat release during the Polymerization process, so that Polymerization kinetics could be greatly improved compared to the pure photochemical mode. These dyes can be proposed as alternatives to the well-established cyanine dyes, more commonly used for the photoPolymerization of (meth)acrylates under NIR light.
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simultaneous initiation of radical and cationic Polymerization Reactions using the g1 copper complex as photoredox catalyst applications of free radical cationic hybrid photoPolymerization in the composites and 3d printing fields
Progress in Organic Coatings, 2019Co-Authors: Frédéric Dumur, Fabrice Morletsavary, Celine Dietlin, Haifaa Mokbel, D Anderson, R Plenderleith, Didier GigmesAbstract:Abstract This investigation presents the use of a photoredox catalyst "G1" as a photoinitiating system for free radical/cationic hybrid Polymerization under mild irradiation conditions. The G1 system (G1/iodonium salt/N-vinylcarbazole), can simultaneously initiate the free radical and cationic Polymerization Reactions upon exposure to a visible (405 nm) light from a Light Emitting Diode (LED) source. The multicomponent G1 system is able to simultaneously generate radical and cationic species through a catalytic photoredox process. The curing of thin samples (25 μm), thick samples (1.4 mm) as well as the manufacture of hybrid system/glass fibers composites (˜2 to 4 mm thickness) was realized and the influence of the ratio of cationic/radical monomer blends on the Polymerization kinetics was studied. The use of G1 in visible light photoinitiating system for the access to composites and 3D printing experiments was particularly outlined. G1 was also shown to have low levels of migration from the cured materials. When compared to reference materials ("F1", a similar copper complex and an anthracene derivative, dibutoxy anthracene), G1 showed better Polymerization efficiency. The initiation efficiency was investigated through the real-time Fourier transform infrared (RT-FTIR) spectroscopy and optical pyrometry. Dynamical Mechanical Analysis has been used to determine the glass temperature transition of the cured hybrid system as a complementary technique.
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photocatalysts in Polymerization Reactions
Chemcatchem, 2016Co-Authors: Nicolas Zivic, Didier Gigmes, Frédéric Dumur, Jean-pierre Fouassier, Mariem Bouzratizerelli, Anthony Kermagoret, Jacques LaleveeAbstract:A short review of the role of photocatalysts in photoPolymerization Reactions is presented. A special emphasis is placed on photoredox catalysts leading to i) high-performance initiating systems for Polymerization upon low light intensity for the use of light emitting diodes (LEDs) and/or visible light and ii) controlled radical photoPolymerization (CRP2) processes with formation/reactivation of dormant species triggered by light.
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naphthalimide phthalimide derivative based photoinitiating systems for Polymerization Reactions under blue lights
Journal of Polymer Science Part A, 2015Co-Authors: Pu Xiao, Bernadette Graff, Didier Gigmes, Frédéric Dumur, Jean-pierre Fouassier, Jing Zhang, Jacques LaleveeAbstract:Naphthalimide-phthalimide derivatives (NDPDs) have been synthesized and combined with an iodonium salt, N-vinylcarbazole, amine or 2,4,6-tris(trichloromethyl)-1,3,5-triazine to produce reactive species (i.e., radicals and cations). These generated reactive species are capable of initiating the cationic Polymerization of epoxides and/or the radical Polymerization of acrylates upon exposure to very soft polychromatic visible lights or blue lights. Compared with the well-known camphorquinone based systems used as references, the novel NDPD based combinations employed here demonstrate clearly higher efficiencies for the cationic Polymerization of epoxides under air as well as the radical Polymerization of acrylates. Remarkably, one of the NDPDs (i.e., NDPD2) based systems is characterized by an outstanding reactivity. The structure/reactivity/efficiency relationships of the investigated NDPDs were studied by fluorescence, cyclic voltammetry, laser flash photolysis, electron spin resonance spin trapping, and steady state photolysis techniques. The key parameters for their reactivity are provided. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 665–674
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Naphthalimide‐phthalimide derivative based photoinitiating systems for Polymerization Reactions under blue lights
Journal of Polymer Science Part A, 2014Co-Authors: Pu Xiao, Bernadette Graff, Didier Gigmes, Frédéric Dumur, Jean-pierre Fouassier, Jing Zhang, Jacques LaleveeAbstract:Naphthalimide-phthalimide derivatives (NDPDs) have been synthesized and combined with an iodonium salt, N-vinylcarbazole, amine or 2,4,6-tris(trichloromethyl)-1,3,5-triazine to produce reactive species (i.e., radicals and cations). These generated reactive species are capable of initiating the cationic Polymerization of epoxides and/or the radical Polymerization of acrylates upon exposure to very soft polychromatic visible lights or blue lights. Compared with the well-known camphorquinone based systems used as references, the novel NDPD based combinations employed here demonstrate clearly higher efficiencies for the cationic Polymerization of epoxides under air as well as the radical Polymerization of acrylates. Remarkably, one of the NDPDs (i.e., NDPD2) based systems is characterized by an outstanding reactivity. The structure/reactivity/efficiency relationships of the investigated NDPDs were studied by fluorescence, cyclic voltammetry, laser flash photolysis, electron spin resonance spin trapping, and steady state photolysis techniques. The key parameters for their reactivity are provided. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 665–674
Fabrice Morletsavary - One of the best experts on this subject based on the ideXlab platform.
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simultaneous initiation of radical and cationic Polymerization Reactions using the g1 copper complex as photoredox catalyst applications of free radical cationic hybrid photoPolymerization in the composites and 3d printing fields
Progress in Organic Coatings, 2019Co-Authors: Frédéric Dumur, Fabrice Morletsavary, Celine Dietlin, Haifaa Mokbel, D Anderson, R Plenderleith, Didier GigmesAbstract:Abstract This investigation presents the use of a photoredox catalyst "G1" as a photoinitiating system for free radical/cationic hybrid Polymerization under mild irradiation conditions. The G1 system (G1/iodonium salt/N-vinylcarbazole), can simultaneously initiate the free radical and cationic Polymerization Reactions upon exposure to a visible (405 nm) light from a Light Emitting Diode (LED) source. The multicomponent G1 system is able to simultaneously generate radical and cationic species through a catalytic photoredox process. The curing of thin samples (25 μm), thick samples (1.4 mm) as well as the manufacture of hybrid system/glass fibers composites (˜2 to 4 mm thickness) was realized and the influence of the ratio of cationic/radical monomer blends on the Polymerization kinetics was studied. The use of G1 in visible light photoinitiating system for the access to composites and 3D printing experiments was particularly outlined. G1 was also shown to have low levels of migration from the cured materials. When compared to reference materials ("F1", a similar copper complex and an anthracene derivative, dibutoxy anthracene), G1 showed better Polymerization efficiency. The initiation efficiency was investigated through the real-time Fourier transform infrared (RT-FTIR) spectroscopy and optical pyrometry. Dynamical Mechanical Analysis has been used to determine the glass temperature transition of the cured hybrid system as a complementary technique.
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photoinduced thermal Polymerization Reactions
Macromolecules, 2018Co-Authors: Audeheloise Bonardi, Frédéric Dumur, Jean-pierre Fouassier, Fabrice Morletsavary, Fabien Bonardi, Celine Dietlin, Guillaume Noirbent, Trevor M Grant, Benoit H LessardAbstract:The combination of thermally induced and photoinduced free radical Polymerization of (meth)acrylic monomers has only been scarcely presented in the literature. In this study, a two-component system with a near-infrared (NIR) dye combined with a thermal initiator is presented. The dye acts as a very efficient heat generator (heater) upon irradiation with NIR light. Several thermal initiators are presented such as an alkoxyamine (e.g., BlocBuilder-MA), azo derivatives, and (hydro)peroxides. The heat delivered by the dye dissociates the thermal initiator, which initiates the free radical Polymerization of (meth)acrylates. Several types of heat generators are presented such as borate-based dyes and a silicon phthalocyanine derivative. For the first time, the effects of the NIR heater concentration, light intensity, and monomer structure on the heat released are studied using thermal imaging studies. NIR light curing is challenging but offers significant advantages: it is safer than shorter wavelength, and it ...
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new chromone based photoinitiators for Polymerization Reactions under visible light
Polymer Chemistry, 2013Co-Authors: Mohamadali Tehfe, Bernadette Graff, Didier Gigmes, Frédéric Dumur, Jean-pierre Fouassier, Pu Xiao, Fabrice Morletsavary, Jacques LaleveeAbstract:Novel photoinitiators derived from a chromone structure are proposed for the free radical Polymerization of acrylates and the free radical promoted cationic Polymerization of epoxides upon exposure to a 457 nm laser diode and even under soft irradiation conditions (blue LED bulb at 462 nm and halogen lamp). Good Polymerization profiles are obtained. These original dyes exhibit a push–pull molecular character as revealed by MO calculations. The initiation mechanisms are analyzed through ESR, fluorescence and laser flash photolysis experiments.
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photoredox catalysis for Polymerization Reactions
Chimia, 2012Co-Authors: Jacques Lalevee, Bernadette Graff, Didier Gigmes, Frédéric Dumur, Mohamadali Tehfe, Fabrice Morletsavary, Nicolas Blanchard, Jean-pierre FouassierAbstract:Photoredox catalysis is now well-known in organic synthesis for the formation of free radicals under very soft irradiations conditions (e.g. sunlight, household fluorescence or LED bulbs, Xe lamp). This method has been introduced here to the polymer chemistry area to initiate ring opening Polymerizations (ROP) or free radical Polymerizations (FRP). The present paper will give an up-to date situation of the photocatalyst achievements in FRP and ROP
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tunable organophotocatalysts for Polymerization Reactions under visible lights
Macromolecules, 2012Co-Authors: Mohamadali Tehfe, Bernadette Graff, Jacques Lalevee, Fabrice Morletsavary, Nicolas Blanchard, Jean-pierre FouassierAbstract:New organic photocatalysts derived from pyrene, anthracene, naphthacene, and pentacene are presented here for the formation of free radicals through a photoredox catalysis. These OPCs can work according to an oxidative cycle in a three component system in combination with diphenyl iodonium salt and a silane or in a reductive cycle in combination with amine and alkyl halide. This OPC behavior is highlighted through an investigation of the associated excited state and redox properties. The free radicals generated are characterized by ESR or photolysis experiments. Upon household LED bulb or Xe lamp exposure, the oxidative three-component system is able to promote the ring-opening Polymerization ROP of an epoxide whereas the reductive three-component system is very efficient to initiate the free radical photoPolymerization FRP of an acrylate. This ability of OPCs to initiate different Polymerization Reactions (ROP and FRP) is clearly an outstanding property.