The Experts below are selected from a list of 1287 Experts worldwide ranked by ideXlab platform
Jacques Lalevée - One of the best experts on this subject based on the ideXlab platform.
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Silane/Iodonium Salt as redox/thermal/photoinitiating systems in radical and cationic polymerizations for laser write and composites
Polymer Chemistry, 2020Co-Authors: Dengxia Wang, Jean Pierre Fouassier, Patxi Garra, Jacques LalevéeAbstract:Initiating systems that can be applied to both free radical polymerization (FRP) and cationic polymerization (CP) have attracted much attention due to their unique advantages, such as integrating monomers with completely different structures and properties into a polymerization system to form high-performance and multi-functional (co)polymers. Methylphenylsilane (MPS) and octadecylsilane (ODS) are originally proposed here combined with Iodonium Salt as a highly versatile triple initiating system for redox, photo and thermal polymerizations (both radical and cationic). In redox polymerization, gel times can be controlled between 1 and 30 min by adjusting the concentrations of silane/Iodonium couples or by adding additives (e.g. stabilizer TEMPOL or different inorganic Salts). The combination of silane/Iod with a photoinitiator results in excellent dual photo/thermal initiating ability for both FRP and CP (demonstrated by DSC and RT-FTIR). These newly developed initiating systems can be applied in laser write experiments @405 nm and show excellent spatial resolution performance. Thick carbon or glass fiber/epoxy resin composites are also easily manufactured via a dual approach (first photocuring at the surface and then thermal curing in depth). Importantly, the new initiating systems show excellent storage stability in epoxide resins, which cannot be achieved with classical initiators.
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silane Iodonium Salt as redox thermal photoinitiating systems in radical and cationic polymerizations for laser write and composites
Polymer Chemistry, 2020Co-Authors: Jacques Lalevée, Jean Pierre Fouassier, Dengxia Wang, Patxi GarraAbstract:Initiating systems that can be applied to both free radical polymerization (FRP) and cationic polymerization (CP) have attracted much attention due to their unique advantages, such as integrating monomers with completely different structures and properties into a polymerization system to form high-performance and multi-functional (co)polymers. Methylphenylsilane (MPS) and octadecylsilane (ODS) are originally proposed here combined with Iodonium Salt as a highly versatile triple initiating system for redox, photo and thermal polymerizations (both radical and cationic). In redox polymerization, gel times can be controlled between 1 and 30 min by adjusting the concentrations of silane/Iodonium couples or by adding additives (e.g. stabilizer TEMPOL or different inorganic Salts). The combination of silane/Iod with a photoinitiator results in excellent dual photo/thermal initiating ability for both FRP and CP (demonstrated by DSC and RT-FTIR). These newly developed initiating systems can be applied in laser write experiments @405 nm and show excellent spatial resolution performance. Thick carbon or glass fiber/epoxy resin composites are also easily manufactured via a dual approach (first photocuring at the surface and then thermal curing in depth). Importantly, the new initiating systems show excellent storage stability in epoxide resins, which cannot be achieved with classical initiators.
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Design of Iodonium Salts for UV or Near-UV LEDs for Photoacid Generator and Polymerization Purposes
Molecules, 2020Co-Authors: Ségolène Villotte, Frédéric Dumur, Didier Gigmes, Jacques LalevéeAbstract:Iodonium Salts are well established photoacid generators, cationic photoinitiators, as well as additives commonly used in photoredox catalytic cycles. However, as a strong limitation, Iodonium Salts are characterized by low light absorption properties for λ > 300 nm so that these latter cannot be activated with cheap, safe, and eco-friendly near UV or even visible light emitting diodes (LEDs). To overcome this drawback, the covalent linkage of an Iodonium Salt to a chromophore absorbing at longer wavelength is actively researched. With aim at red-shifting the absorption spectrum of the Iodonium Salt, the synthesis of new compounds combining within a unique chemical structure both the chromophore (here the naphthalimide scaffold) and the Iodonium Salt is presented. By mean of this strategy, a polymerization could be initiated at 365 nm with the modified Iodonium Salts whereas no polymerization could be induced with the benchmark Iodonium Salt i.e., Speedcure 938 at this specific wavelength. To examine the effect of the counter-anion on the photoinitiating ability of these different Salts, five different counter-anions were used. Comparison between the different anions revealed the bis(trifluoromethane)sulfonimide Salt to exhibit the best photoinitiating ability in both the free radical polymerization of acrylates and the cationic polymerization of epoxides. To support the experimental results, molecular orbital calculations have been carried out. By theoretical calculations, the initiating species resulting from the photocleavage of the Iodonium Salts could be determined. The cleavage selectivity and the photochemical reactivity of the new Iodoniums are also discussed.
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Remarkable Versatility of Silane/Iodonium Salt asRedox Free Radical, Cationic, and Photopolymerization Initiators
Macromolecules, 2019Co-Authors: Dengxia Wang, Jean Pierre Fouassier, Florian Szillat, Jacques LalevéeAbstract:The use of safe, economic, and efficient initiators in redox free radical polymerization (RFRP) at room temperature (RT) or in cationic polymerization (CP) and as photoinitiators (PI) for both free radical polymerization (FRP) and CP as well as their use for the manufacture of composites are investigated. Remarkably, initiators based on silane/Iodonium Salt couples are proposed here for their versatility for all the different polymerization modes which is a quite unique feature. The reactions are followed by optical pyrometric measurements, DSC (differential scanning calorimetry), RT-FTIR (real-time Fourier transformed infrared spectrometry), and CRM (confocal Raman microscopy). In RFRP, an adjustable gel time can be controlled between 1 and 15 min by adjusting the concentrations of these redox agents (or even between 2 and 30 min upon addition of stabilizer, e.g., TEMPOL); the storage stability over 5 weeks at ambient temperature and in the dark is excellent. In FRP, up to 80% of reactive function conver...
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remarkable versatility of silane Iodonium Salt asredox free radical cationic and photopolymerization initiators
Macromolecules, 2019Co-Authors: Jacques Lalevée, Jean Pierre Fouassier, Dengxia Wang, Florian SzillatAbstract:The use of safe, economic, and efficient initiators in redox free radical polymerization (RFRP) at room temperature (RT) or in cationic polymerization (CP) and as photoinitiators (PI) for both free radical polymerization (FRP) and CP as well as their use for the manufacture of composites are investigated. Remarkably, initiators based on silane/Iodonium Salt couples are proposed here for their versatility for all the different polymerization modes which is a quite unique feature. The reactions are followed by optical pyrometric measurements, DSC (differential scanning calorimetry), RT-FTIR (real-time Fourier transformed infrared spectrometry), and CRM (confocal Raman microscopy). In RFRP, an adjustable gel time can be controlled between 1 and 15 min by adjusting the concentrations of these redox agents (or even between 2 and 30 min upon addition of stabilizer, e.g., TEMPOL); the storage stability over 5 weeks at ambient temperature and in the dark is excellent. In FRP, up to 80% of reactive function conver...
Jean Pierre Fouassier - One of the best experts on this subject based on the ideXlab platform.
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silane Iodonium Salt as redox thermal photoinitiating systems in radical and cationic polymerizations for laser write and composites
Polymer Chemistry, 2020Co-Authors: Jacques Lalevée, Jean Pierre Fouassier, Dengxia Wang, Patxi GarraAbstract:Initiating systems that can be applied to both free radical polymerization (FRP) and cationic polymerization (CP) have attracted much attention due to their unique advantages, such as integrating monomers with completely different structures and properties into a polymerization system to form high-performance and multi-functional (co)polymers. Methylphenylsilane (MPS) and octadecylsilane (ODS) are originally proposed here combined with Iodonium Salt as a highly versatile triple initiating system for redox, photo and thermal polymerizations (both radical and cationic). In redox polymerization, gel times can be controlled between 1 and 30 min by adjusting the concentrations of silane/Iodonium couples or by adding additives (e.g. stabilizer TEMPOL or different inorganic Salts). The combination of silane/Iod with a photoinitiator results in excellent dual photo/thermal initiating ability for both FRP and CP (demonstrated by DSC and RT-FTIR). These newly developed initiating systems can be applied in laser write experiments @405 nm and show excellent spatial resolution performance. Thick carbon or glass fiber/epoxy resin composites are also easily manufactured via a dual approach (first photocuring at the surface and then thermal curing in depth). Importantly, the new initiating systems show excellent storage stability in epoxide resins, which cannot be achieved with classical initiators.
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Silane/Iodonium Salt as redox/thermal/photoinitiating systems in radical and cationic polymerizations for laser write and composites
Polymer Chemistry, 2020Co-Authors: Dengxia Wang, Jean Pierre Fouassier, Patxi Garra, Jacques LalevéeAbstract:Initiating systems that can be applied to both free radical polymerization (FRP) and cationic polymerization (CP) have attracted much attention due to their unique advantages, such as integrating monomers with completely different structures and properties into a polymerization system to form high-performance and multi-functional (co)polymers. Methylphenylsilane (MPS) and octadecylsilane (ODS) are originally proposed here combined with Iodonium Salt as a highly versatile triple initiating system for redox, photo and thermal polymerizations (both radical and cationic). In redox polymerization, gel times can be controlled between 1 and 30 min by adjusting the concentrations of silane/Iodonium couples or by adding additives (e.g. stabilizer TEMPOL or different inorganic Salts). The combination of silane/Iod with a photoinitiator results in excellent dual photo/thermal initiating ability for both FRP and CP (demonstrated by DSC and RT-FTIR). These newly developed initiating systems can be applied in laser write experiments @405 nm and show excellent spatial resolution performance. Thick carbon or glass fiber/epoxy resin composites are also easily manufactured via a dual approach (first photocuring at the surface and then thermal curing in depth). Importantly, the new initiating systems show excellent storage stability in epoxide resins, which cannot be achieved with classical initiators.
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Remarkable Versatility of Silane/Iodonium Salt asRedox Free Radical, Cationic, and Photopolymerization Initiators
Macromolecules, 2019Co-Authors: Dengxia Wang, Jean Pierre Fouassier, Florian Szillat, Jacques LalevéeAbstract:The use of safe, economic, and efficient initiators in redox free radical polymerization (RFRP) at room temperature (RT) or in cationic polymerization (CP) and as photoinitiators (PI) for both free radical polymerization (FRP) and CP as well as their use for the manufacture of composites are investigated. Remarkably, initiators based on silane/Iodonium Salt couples are proposed here for their versatility for all the different polymerization modes which is a quite unique feature. The reactions are followed by optical pyrometric measurements, DSC (differential scanning calorimetry), RT-FTIR (real-time Fourier transformed infrared spectrometry), and CRM (confocal Raman microscopy). In RFRP, an adjustable gel time can be controlled between 1 and 15 min by adjusting the concentrations of these redox agents (or even between 2 and 30 min upon addition of stabilizer, e.g., TEMPOL); the storage stability over 5 weeks at ambient temperature and in the dark is excellent. In FRP, up to 80% of reactive function conver...
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remarkable versatility of silane Iodonium Salt asredox free radical cationic and photopolymerization initiators
Macromolecules, 2019Co-Authors: Jacques Lalevée, Jean Pierre Fouassier, Dengxia Wang, Florian SzillatAbstract:The use of safe, economic, and efficient initiators in redox free radical polymerization (RFRP) at room temperature (RT) or in cationic polymerization (CP) and as photoinitiators (PI) for both free radical polymerization (FRP) and CP as well as their use for the manufacture of composites are investigated. Remarkably, initiators based on silane/Iodonium Salt couples are proposed here for their versatility for all the different polymerization modes which is a quite unique feature. The reactions are followed by optical pyrometric measurements, DSC (differential scanning calorimetry), RT-FTIR (real-time Fourier transformed infrared spectrometry), and CRM (confocal Raman microscopy). In RFRP, an adjustable gel time can be controlled between 1 and 15 min by adjusting the concentrations of these redox agents (or even between 2 and 30 min upon addition of stabilizer, e.g., TEMPOL); the storage stability over 5 weeks at ambient temperature and in the dark is excellent. In FRP, up to 80% of reactive function conver...
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3-Hydroxyflavone and N-Phenylglycine in High Performance Photoinitiating Systems for 3D Printing and Photocomposites Synthesis
Macromolecules, 2018Co-Authors: Assi Al Mousawi, Bernadette Graff, Jean Pierre Fouassier, Patxi Garra, Frédéric Dumur, Joumana Toufaily, Tayssir Hamieh, Michael Schmitt, Jacques LalevéeAbstract:We propose to use 3-hydroxyflavone as a versatile high performance visible light photoinitiator (PI) in combination with an amino acid (N-phenylglycine) for the free radical polymerization (FRP) of methacrylates in thick samples (e.g., 3D printing) or composites upon visible light exposure (light-emitting diode LED@405 nm or LED@477 nm). The high originality of this approach is the use of safer compounds in photoinitiating systems (combination flavone derivative/amino acid). 3-Hydroxyflavone can also be used in three-component systems with an Iodonium Salt and an amine for the cationic polymerization of epoxides upon exposure to near-UV light LED@385 nm. Also interestingly, a charge transfer complex (CTC) between N-phenylglycine NPG and Iodonium Salt gives also remarkable initiating performance for free radical polymerization of methacrylates upon mild light irradiation conditions (LED@405 nm). High polymerization initiating abilities are found, and high final reactive function conversions are obtained. T...
Didier Gigmes - One of the best experts on this subject based on the ideXlab platform.
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Design of Iodonium Salts for UV or Near-UV LEDs for Photoacid Generator and Polymerization Purposes
Molecules, 2020Co-Authors: Ségolène Villotte, Frédéric Dumur, Didier Gigmes, Jacques LalevéeAbstract:Iodonium Salts are well established photoacid generators, cationic photoinitiators, as well as additives commonly used in photoredox catalytic cycles. However, as a strong limitation, Iodonium Salts are characterized by low light absorption properties for λ > 300 nm so that these latter cannot be activated with cheap, safe, and eco-friendly near UV or even visible light emitting diodes (LEDs). To overcome this drawback, the covalent linkage of an Iodonium Salt to a chromophore absorbing at longer wavelength is actively researched. With aim at red-shifting the absorption spectrum of the Iodonium Salt, the synthesis of new compounds combining within a unique chemical structure both the chromophore (here the naphthalimide scaffold) and the Iodonium Salt is presented. By mean of this strategy, a polymerization could be initiated at 365 nm with the modified Iodonium Salts whereas no polymerization could be induced with the benchmark Iodonium Salt i.e., Speedcure 938 at this specific wavelength. To examine the effect of the counter-anion on the photoinitiating ability of these different Salts, five different counter-anions were used. Comparison between the different anions revealed the bis(trifluoromethane)sulfonimide Salt to exhibit the best photoinitiating ability in both the free radical polymerization of acrylates and the cationic polymerization of epoxides. To support the experimental results, molecular orbital calculations have been carried out. By theoretical calculations, the initiating species resulting from the photocleavage of the Iodonium Salts could be determined. The cleavage selectivity and the photochemical reactivity of the new Iodoniums are also discussed.
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Design of Iodonium Salts for UV or Near-UV LEDs for Photoacid Generator and Polymerization Purposes.
Molecules, 2019Co-Authors: Ségolène Villotte, Frédéric Dumur, Didier Gigmes, Jacques LalevéeAbstract:Iodonium Salts are well established photoacid generators, cationic photoinitiators, as well as additives commonly used in photoredox catalytic cycles. However, as a strong limitation, Iodonium Salts are characterized by low light absorption properties for lambda \textgreater 300 nm so that these latter cannot be activated with cheap, safe, and eco-friendly near UV or even visible light emitting diodes (LEDs). To overcome this drawback, the covalent linkage of an Iodonium Salt to a chromophore absorbing at longer wavelength is actively researched. With aim at red-shifting the absorption spectrum of the Iodonium Salt, the synthesis of new compounds combining within a unique chemical structure both the chromophore (here the naphthalimide scaffold) and the Iodonium Salt is presented. By mean of this strategy, a polymerization could be initiated at 365 nm with the modified Iodonium Salts whereas no polymerization could be induced with the benchmark Iodonium Salt i.e., Speedcure 938 at this specific wavelength. To examine the effect of the counter-anion on the photoinitiating ability of these different Salts, five different counter-anions were used. Comparison between the different anions revealed the bis(trifluoromethane)sulfonimide Salt to exhibit the best photoinitiating ability in both the free radical polymerization of acrylates and the cationic polymerization of epoxides. To support the experimental results, molecular orbital calculations have been carried out. By theoretical calculations, the initiating species resulting from the photocleavage of the Iodonium Salts could be determined. The cleavage selectivity and the photochemical reactivity of the new Iodoniums are also discussed.
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Copper-Based (Photo)redox Initiating Systems as Highly Efficient Systems for Interpenetrating Polymer Network Preparation
Macromolecules, 2018Co-Authors: Patxi Garra, Fabrice Morlet-savary, Jean Pierre Fouassier, Céline Dietlin, Frédéric Dumur, Didier Gigmes, Méline Carré, Jacques LalevéeAbstract:Simultaneous redox free radical polymerization (FRP) and redox cationic polymerization (CP) are combined for the synthesis of methacrylate/diepoxide interpenetrating polymer networks (IPN). At first, the Cu(acac)2/phosphine/Iodonium Salt operates according to the principles of free radical promoted cationic polymerization (FRPCP). A photoactivation of the reaction for that system was necessary to enhance the mild methacrylate and diepoxide conversions. Second and at least, two complementary copper catalytic cycles are used simultaneously: the recently developed Cu(II)/reducing agent/peroxide FRP system combined with the older Cu(II)/reducing agent/Iodonium Salt redox CP system. For this latter hybrid system, outstanding efficiency was observed with more than 90% of epoxy functions conversion for the cationic difunctional monomers and 78% conversion for the vinylic functions conversion for difunctional monomers. The radical and cation generations are discussed in order to fill the interrogations raised by ...
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Copper (Photo)redox Catalyst for Radical Photopolymerization in Shadowed Areas and Access to Thick and Filled Samples
Macromolecules, 2017Co-Authors: Patxi Garra, Fabrice Morlet-savary, Jean Pierre Fouassier, Céline Dietlin, Frédéric Dumur, Didier Gigmes, A. Al Mousawi, Jacques LalevéeAbstract:The free radical polymerization of low viscosity methacrylate blends upon a LED irradiation at 405 nm under air is carried out using Cu(I)/Iodonium Salt/tin(II) organic derivative as photoinitiating systems. The system exhibits a high reactivity; where tin derivative plays a crucial role. It operates through a catalytic cycle in which Cu(I) is regenerated and can be used at low concentrations (0.1–0.3 wt %). Remarkable performances are achieved. At first, a final methacrylate conversion of 82% after 40 s in 1.4 mm thick samples is obtained for an irradiance of 35 mW/cm2 whereas such a conversion is only reached only when using a Cu(I)/Iodonium Salt system under a 200 mW/cm2 light exposure. Second, a 55% conversion is still obtained after 150 s under a very low irradiance (2.5 mW/cm2). Third, almost tack-free thick samples (1.4 mm) under air are produced upon sunlight exposure (65% of conversion for the 1.4 mm thick sample after 90 s of irradiation). Fourth, the photocuring of clear samples as thick as 9 c...
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a novel naphthalimide scaffold based Iodonium Salt as a one component photoacid photoinitiator for cationic and radical polymerization under led exposure
Polymer Chemistry, 2016Co-Authors: Nicolas Zivic, Jean Pierre Fouassier, Fabrice Morletsavary, Ségolène Villotte, Céline Dietlin, Frédéric Dumur, Didier Gigmes, M Bouzratizerrelli, Jacques LalevéeAbstract:A strong drawback of the photoinitiators of cationic polymerization or photoacids is the photosensitivity for short and energetic wavelengths preventing their general use (specialized photochemical equipment with safety concerns must be used). In the present paper, a novel Iodonium Salt bearing a naphthalimide moiety (naphthalimide-Ph-I+-Ph) is proposed as a one-component photoinitiator/photoacid operating at longer and safer wavelengths (i.e. violet light emitting diodes at 365, 385 nm and 395 nm). It allows the polymerization of various formulations (methacrylates, epoxides, vinyl ethers). A high reactive function conversion for multifunctional monomers can be achieved: e.g. 50% for a diepoxide under air, >90% for a divinylether (with a very high rate of polymerization Rp), almost 100% for an epoxide/vinyl ether blend (very high Rp) under air, and 85% for methacrylates (high Rp) in laminate (43% under air). These results are above the ones obtained with a thianthrenium Salt chosen as a reference e.g. a lower epoxy conversion ∼25% and a clearly lower Rp for the diepoxide polymerization. ESR-spin trapping, laser flash photolysis, steady state photolysis and molecular orbitals calculations support the formation of Ph˙ and naphthalimide-Ph-I˙+ as well as the generation of H+, thereby explaining the photoinitiation step mechanism.
Frédéric Dumur - One of the best experts on this subject based on the ideXlab platform.
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Design of Iodonium Salts for UV or Near-UV LEDs for Photoacid Generator and Polymerization Purposes
Molecules, 2020Co-Authors: Ségolène Villotte, Frédéric Dumur, Didier Gigmes, Jacques LalevéeAbstract:Iodonium Salts are well established photoacid generators, cationic photoinitiators, as well as additives commonly used in photoredox catalytic cycles. However, as a strong limitation, Iodonium Salts are characterized by low light absorption properties for λ > 300 nm so that these latter cannot be activated with cheap, safe, and eco-friendly near UV or even visible light emitting diodes (LEDs). To overcome this drawback, the covalent linkage of an Iodonium Salt to a chromophore absorbing at longer wavelength is actively researched. With aim at red-shifting the absorption spectrum of the Iodonium Salt, the synthesis of new compounds combining within a unique chemical structure both the chromophore (here the naphthalimide scaffold) and the Iodonium Salt is presented. By mean of this strategy, a polymerization could be initiated at 365 nm with the modified Iodonium Salts whereas no polymerization could be induced with the benchmark Iodonium Salt i.e., Speedcure 938 at this specific wavelength. To examine the effect of the counter-anion on the photoinitiating ability of these different Salts, five different counter-anions were used. Comparison between the different anions revealed the bis(trifluoromethane)sulfonimide Salt to exhibit the best photoinitiating ability in both the free radical polymerization of acrylates and the cationic polymerization of epoxides. To support the experimental results, molecular orbital calculations have been carried out. By theoretical calculations, the initiating species resulting from the photocleavage of the Iodonium Salts could be determined. The cleavage selectivity and the photochemical reactivity of the new Iodoniums are also discussed.
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Design of Iodonium Salts for UV or Near-UV LEDs for Photoacid Generator and Polymerization Purposes.
Molecules, 2019Co-Authors: Ségolène Villotte, Frédéric Dumur, Didier Gigmes, Jacques LalevéeAbstract:Iodonium Salts are well established photoacid generators, cationic photoinitiators, as well as additives commonly used in photoredox catalytic cycles. However, as a strong limitation, Iodonium Salts are characterized by low light absorption properties for lambda \textgreater 300 nm so that these latter cannot be activated with cheap, safe, and eco-friendly near UV or even visible light emitting diodes (LEDs). To overcome this drawback, the covalent linkage of an Iodonium Salt to a chromophore absorbing at longer wavelength is actively researched. With aim at red-shifting the absorption spectrum of the Iodonium Salt, the synthesis of new compounds combining within a unique chemical structure both the chromophore (here the naphthalimide scaffold) and the Iodonium Salt is presented. By mean of this strategy, a polymerization could be initiated at 365 nm with the modified Iodonium Salts whereas no polymerization could be induced with the benchmark Iodonium Salt i.e., Speedcure 938 at this specific wavelength. To examine the effect of the counter-anion on the photoinitiating ability of these different Salts, five different counter-anions were used. Comparison between the different anions revealed the bis(trifluoromethane)sulfonimide Salt to exhibit the best photoinitiating ability in both the free radical polymerization of acrylates and the cationic polymerization of epoxides. To support the experimental results, molecular orbital calculations have been carried out. By theoretical calculations, the initiating species resulting from the photocleavage of the Iodonium Salts could be determined. The cleavage selectivity and the photochemical reactivity of the new Iodoniums are also discussed.
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3-Hydroxyflavone and N-Phenylglycine in High Performance Photoinitiating Systems for 3D Printing and Photocomposites Synthesis
Macromolecules, 2018Co-Authors: Assi Al Mousawi, Bernadette Graff, Jean Pierre Fouassier, Patxi Garra, Frédéric Dumur, Joumana Toufaily, Tayssir Hamieh, Michael Schmitt, Jacques LalevéeAbstract:We propose to use 3-hydroxyflavone as a versatile high performance visible light photoinitiator (PI) in combination with an amino acid (N-phenylglycine) for the free radical polymerization (FRP) of methacrylates in thick samples (e.g., 3D printing) or composites upon visible light exposure (light-emitting diode LED@405 nm or LED@477 nm). The high originality of this approach is the use of safer compounds in photoinitiating systems (combination flavone derivative/amino acid). 3-Hydroxyflavone can also be used in three-component systems with an Iodonium Salt and an amine for the cationic polymerization of epoxides upon exposure to near-UV light LED@385 nm. Also interestingly, a charge transfer complex (CTC) between N-phenylglycine NPG and Iodonium Salt gives also remarkable initiating performance for free radical polymerization of methacrylates upon mild light irradiation conditions (LED@405 nm). High polymerization initiating abilities are found, and high final reactive function conversions are obtained. T...
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Copper-Based (Photo)redox Initiating Systems as Highly Efficient Systems for Interpenetrating Polymer Network Preparation
Macromolecules, 2018Co-Authors: Patxi Garra, Fabrice Morlet-savary, Jean Pierre Fouassier, Céline Dietlin, Frédéric Dumur, Didier Gigmes, Méline Carré, Jacques LalevéeAbstract:Simultaneous redox free radical polymerization (FRP) and redox cationic polymerization (CP) are combined for the synthesis of methacrylate/diepoxide interpenetrating polymer networks (IPN). At first, the Cu(acac)2/phosphine/Iodonium Salt operates according to the principles of free radical promoted cationic polymerization (FRPCP). A photoactivation of the reaction for that system was necessary to enhance the mild methacrylate and diepoxide conversions. Second and at least, two complementary copper catalytic cycles are used simultaneously: the recently developed Cu(II)/reducing agent/peroxide FRP system combined with the older Cu(II)/reducing agent/Iodonium Salt redox CP system. For this latter hybrid system, outstanding efficiency was observed with more than 90% of epoxy functions conversion for the cationic difunctional monomers and 78% conversion for the vinylic functions conversion for difunctional monomers. The radical and cation generations are discussed in order to fill the interrogations raised by ...
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Copper (Photo)redox Catalyst for Radical Photopolymerization in Shadowed Areas and Access to Thick and Filled Samples
Macromolecules, 2017Co-Authors: Patxi Garra, Fabrice Morlet-savary, Jean Pierre Fouassier, Céline Dietlin, Frédéric Dumur, Didier Gigmes, A. Al Mousawi, Jacques LalevéeAbstract:The free radical polymerization of low viscosity methacrylate blends upon a LED irradiation at 405 nm under air is carried out using Cu(I)/Iodonium Salt/tin(II) organic derivative as photoinitiating systems. The system exhibits a high reactivity; where tin derivative plays a crucial role. It operates through a catalytic cycle in which Cu(I) is regenerated and can be used at low concentrations (0.1–0.3 wt %). Remarkable performances are achieved. At first, a final methacrylate conversion of 82% after 40 s in 1.4 mm thick samples is obtained for an irradiance of 35 mW/cm2 whereas such a conversion is only reached only when using a Cu(I)/Iodonium Salt system under a 200 mW/cm2 light exposure. Second, a 55% conversion is still obtained after 150 s under a very low irradiance (2.5 mW/cm2). Third, almost tack-free thick samples (1.4 mm) under air are produced upon sunlight exposure (65% of conversion for the 1.4 mm thick sample after 90 s of irradiation). Fourth, the photocuring of clear samples as thick as 9 c...
Fernanda Nedel - One of the best experts on this subject based on the ideXlab platform.
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Iodonium Salt incorporation in dental adhesives and its relation with degree of conversion, ultimate tensile strength, cell viability, and oxidative stress
Clinical Oral Investigations, 2019Co-Authors: Camila Perelló Ferrúa, Fabrício Aulo Ogliari, Fernanda Barbosa Leal, Marta Oliveira Gazal, Gabriele Cordenonzi Ghisleni, Rodrigo Varella Carvalho, Flávio Fernando Demarco, Fernanda NedelAbstract:Objective The aim of this study was to evaluate the degree of conversion, ultimate tensile strength, cell viability, and oxidative stress of two different ternary initiation systems, using two photoinitiation polymerization times. Methods The groups investigated were camphorquinone (CQ); CQ and diphenyleneIodonium hexafluorophosphate (DPI); CQ and ethyl 4-dimethylamine benzoate (EDAB); and CQ, EDAB, and DPI, with EDAB in high and low concentration. To assess the degree of conversion (DC) and the ultimate tensile strength (UTS), a real-time Fourier transform infrared spectroscopy and a universal test machine Emic DL-500 were used, respectively. Cell viability and oxidative stress were evaluated by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide), superoxide dismutase (SOD), total sulfhydryl (SH) content, and thiobarbituric acid reactive species (TBARS) formation assays. Results Slight lower cell viability was shown when DPI was associated with high concentrations of EDAB; this reduction seemed to be attenuated when lower concentrations of EDAB were used. When EDAB and DPI were associated, no oxidative damage was shown. The degree of conversion was increased in the ternary systems (CQ + EDAB lower concentration + DPI) group, which did not affect the UTS, cytotoxicity, and oxidative stress parameters. The polymerization time did not affect cell viability, total SH, and TBARS; however, a slight increase was shown in SOD levels. Clinical relevance Our study emphasizes the relevance of incorporating the third element—Iodonium Salt—in a binary adhesive systems composed exclusively of CQ and EDAB.
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Iodonium Salt incorporation in dental adhesives and its relation with degree of conversion, ultimate tensile strength, cell viability, and oxidative stress.
Clinical oral investigations, 2018Co-Authors: Camila Perelló Ferrúa, Fabrício Aulo Ogliari, Fernanda B. Leal, Gabriele Cordenonzi Ghisleni, Rodrigo Varella Carvalho, Flávio Fernando Demarco, Marta Gazal, Fernanda NedelAbstract:The aim of this study was to evaluate the degree of conversion, ultimate tensile strength, cell viability, and oxidative stress of two different ternary initiation systems, using two photoinitiation polymerization times. The groups investigated were camphorquinone (CQ); CQ and diphenyleneIodonium hexafluorophosphate (DPI); CQ and ethyl 4-dimethylamine benzoate (EDAB); and CQ, EDAB, and DPI, with EDAB in high and low concentration. To assess the degree of conversion (DC) and the ultimate tensile strength (UTS), a real-time Fourier transform infrared spectroscopy and a universal test machine Emic DL-500 were used, respectively. Cell viability and oxidative stress were evaluated by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide), superoxide dismutase (SOD), total sulfhydryl (SH) content, and thiobarbituric acid reactive species (TBARS) formation assays. Slight lower cell viability was shown when DPI was associated with high concentrations of EDAB; this reduction seemed to be attenuated when lower concentrations of EDAB were used. When EDAB and DPI were associated, no oxidative damage was shown. The degree of conversion was increased in the ternary systems (CQ + EDAB lower concentration + DPI) group, which did not affect the UTS, cytotoxicity, and oxidative stress parameters. The polymerization time did not affect cell viability, total SH, and TBARS; however, a slight increase was shown in SOD levels. Our study emphasizes the relevance of incorporating the third element—Iodonium Salt—in a binary adhesive systems composed exclusively of CQ and EDAB.
