The Experts below are selected from a list of 231 Experts worldwide ranked by ideXlab platform
Richard C. Larock - One of the best experts on this subject based on the ideXlab platform.
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Novel Thermosets prepared by cationic copolymerization of various vegetable oils- : synthesis and their structure-property relationships
Polymer, 2005Co-Authors: Dejan D. Andjelkovic, Marlen Valverde, Phillip Henna, Fengkui Li, Richard C. LarockAbstract:A range of Thermoset Plastics have been prepared by the cationic copolymerization of olive, peanut, sesame, canola, corn, soybean, grapeseed, sunflower, low saturation soy, safflower, walnut, and linseed oils with divinylbenzene or a combination of styrene and divinylbenzene comonomers catalyzed by boron trifluoride diethyl etherate. The chemical, physical, thermal, and mechanical properties of these new polymers have been investigated as a function of the vegetable oil composition. The vegetable oil reactivity has a direct effect on most of the polymers' properties, which can be reasonably predicted by careful choice of the vegetable oil. Coupled with variations in the comonomer and stoichiometry, the choice of vegetable oil allows one to tailor the polymer's properties for specific applications.
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Novel Thermosets prepared by cationic copolymerization of various vegetable oils - Synthesis and their structure-property relationships
Polymer, 2005Co-Authors: Dejan D. Andjelkovic, Marlen Valverde, Phillip Henna, Fengkui Li, Richard C. LarockAbstract:A range of Thermoset Plastics have been prepared by the cationic copolymerization of olive, peanut, sesame, canola, corn, soybean, grapeseed, sunflower, low saturation soy, safflower, walnut, and linseed oils with divinylbenzene or a combination of styrene and divinylbenzene comonomers catalyzed by boron trifluoride diethyl etherate. The chemical, physical, thermal, and mechanical properties of these new polymers have been investigated as a function of the vegetable oil composition. The vegetable oil reactivity has a direct effect on most of the polymers' properties, which can be reasonably predicted by careful choice of the vegetable oil. Coupled with variations in the comonomer and stoichiometry, the choice of vegetable oil allows one to tailor the polymer's properties for specific applications. © 2005 Elsevier Ltd. All rights reserved.
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synthesis of Thermoset Plastics by lewis acid initiated copolymerization of fish oil ethyl esters and alkenes
Journal of Applied Polymer Science, 2001Co-Authors: David W Marks, Fengkui Li, Chad M Pacha, Richard C. LarockAbstract:The Lewis acid initiated cationic homopolymerization of Norway fish oil ethyl ester (NFO) or the corresponding conjugated fish oil (CFO) and their copolymerization with various alkene comonomers is investigated. Among the Lewis acids employed, boron trifluoride diethyl etherate (BFE, BF3 · OEt2) is found to be the most effective initiator for cationic polymerization of the NFO and CFO systems. The BFE-initiated homopolymerization of NFO generally results in low molecular weight viscous oils, while that of CFO leads to a solid elastic gel with a gel time of more than 72 h at room temperature. Copolymerization of the NFO or CFO with some alkene comonomers significantly facilitates gelation. The gel times are largely dependent upon the stoichiometry, the type of fish oil, and the alkene comonomer. After postcuring at elevated temperatures, the cationic copolymerization affords polymers ranging from soft rubbery materials to rigid Plastics. These NFO and CFO polymers are composed of highly crosslinked materials and a certain amount of free oils and are found to be fully cured Thermosets. Generally, CFO polymers appear to be harder than the corresponding NFO polymers. However, the thermal properties of the bulk polymers are similar to each other, and their insoluble extracts exhibit much higher thermal stability than the bulk Thermosets. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2001–2012, 2001
H Wilski - One of the best experts on this subject based on the ideXlab platform.
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the radiation resistance of Thermoset Plastics v epoxy Plastics
International Journal of Radiation Applications and Instrumentation. Part C. Radiation Physics and Chemistry, 1992Co-Authors: H P Gilfrich, H WilskiAbstract:Abstract Flexural strength, impact strength and dielectric properties of an epoxy plastic (bispherol A-based epoxy resin cured with aromatic diamines) with inorganic fillers remained unchanged after irradiation at high dose rate up to 10 MGy. Measurements of heat deflection temperature and sol fraction indicated, however, a deterioration of the resin. The same results were obtained after irradiation in the presence of air at extremely low dose rate (irradiation time: 10 years). Electrical surface resistance and tracking resistance worsened after irradiation. In addition, both of these surface-dependent properties were markedly influenced by the dose rate.
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The radiation resistance of Thermoset Plastics—V. Epoxy Plastics
International Journal of Radiation Applications and Instrumentation. Part C. Radiation Physics and Chemistry, 1992Co-Authors: H P Gilfrich, H WilskiAbstract:Abstract Flexural strength, impact strength and dielectric properties of an epoxy plastic (bispherol A-based epoxy resin cured with aromatic diamines) with inorganic fillers remained unchanged after irradiation at high dose rate up to 10 MGy. Measurements of heat deflection temperature and sol fraction indicated, however, a deterioration of the resin. The same results were obtained after irradiation in the presence of air at extremely low dose rate (irradiation time: 10 years). Electrical surface resistance and tracking resistance worsened after irradiation. In addition, both of these surface-dependent properties were markedly influenced by the dose rate.
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the radiation resistance of Thermoset Plastics vi unsaturated polyester Plastics
International Journal of Radiation Applications and Instrumentation. Part C. Radiation Physics and Chemistry, 1992Co-Authors: H WilskiAbstract:Abstract Samples of two unsaturated polyester Plastics, both with inorganic fillers, were irradiated under two very different conditions. One set of samples was irradiated with electrons, under exclusion of oxygen, using a high dose rate. The second set was irradiated with γ-rays, in air, using a very low dose rate of only 13.8 Gy/h. In the case of the short-term experiment the flexural strength, the impact strength and the deflection temperature passed through maxima as a function of dose. A significant deterioration of the strength did not occur up to a dose of 10 MGy. However, in contrast to this result, in the long-term experiment the strength was remarkably reduced at doses above 0.5 MGy. The electrical properties of four samples of different formulations were investigated. Irradiation with high dose rate had little influence on the electrical properties, but an abrupt drop of the surface resistance was found at 0.1 MGy in the long-term experiment. The tracking resistance showed a similar behaviour. Only the dielectric constants remained unchanged under all conditions of irradiation.
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The radiation resistance of Thermoset Plastics—VI. Unsaturated polyester Plastics
International Journal of Radiation Applications and Instrumentation. Part C. Radiation Physics and Chemistry, 1992Co-Authors: H WilskiAbstract:Abstract Samples of two unsaturated polyester Plastics, both with inorganic fillers, were irradiated under two very different conditions. One set of samples was irradiated with electrons, under exclusion of oxygen, using a high dose rate. The second set was irradiated with γ-rays, in air, using a very low dose rate of only 13.8 Gy/h. In the case of the short-term experiment the flexural strength, the impact strength and the deflection temperature passed through maxima as a function of dose. A significant deterioration of the strength did not occur up to a dose of 10 MGy. However, in contrast to this result, in the long-term experiment the strength was remarkably reduced at doses above 0.5 MGy. The electrical properties of four samples of different formulations were investigated. Irradiation with high dose rate had little influence on the electrical properties, but an abrupt drop of the surface resistance was found at 0.1 MGy in the long-term experiment. The tracking resistance showed a similar behaviour. Only the dielectric constants remained unchanged under all conditions of irradiation.
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the radiation resistance of Thermoset Plastics iv melamine formaldehyde Plastics
International Journal of Radiation Applications and Instrumentation. Part C. Radiation Physics and Chemistry, 1992Co-Authors: H P Gilfrich, S Rosinger, H WilskiAbstract:Abstract Samples of two melamine-formaldehyde Plastics, one filled with asbestos and the other filled with wood flour, were irradiated under two very different conditions. One set of samples was irradiated with electrons, under the exclusion of oxygen, using a high dose rate. The second set was irradiated with γ-rays, in an air environment, using a very low dose rate. This experiment lasted longer than 10 years. Mechanical properties of the asbestos-filled type, measured at room temperature, remained unchanged up to the highest dose and were independent of irradiation conditions. However, polymer deterioration was observed as evidenced by the heat deflection temperature at irradiation doses above 2MGy. The wood-filled samples were considerably deteriorated at doses above 0.1 MGy with the lower dose rate (13.8Gy/h) showing the more severe deterioration. Surface resistance was adversely affected by irradiation but other electrical properties remained unchanged.
Todd Roper - One of the best experts on this subject based on the ideXlab platform.
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Thiol-enes: Chemistry of the past with promise for the future
Journal of Polymer Science Part A: Polymer Chemistry, 2004Co-Authors: C. E. Hoyle, Tai Yeon Lee, Todd RoperAbstract:The photopolymerization of mixtures of multifunctional thiols and enes is an efficient method for the rapid production of films and Thermoset Plastics with unprecedented physical and mechanical properties. One of the major obstacles in traditional free-radical photopolymerization is essentially eliminated in thiol–ene polymerizations because the polymerization occurs in air almost as rapidly as in an inert atmosphere. Virtually any type of ene will participate in a free-radical polymerization process with a multifunctional thiol. Hence, it is possible to tailor materials with virtually any combination of properties required for a particular application. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 5301–5338, 2004
C. P. Reghunadhan Nair - One of the best experts on this subject based on the ideXlab platform.
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Handbook of Thermoset Plastics
Journal of Analytical and Applied Pyrolysis, 2005Co-Authors: Piotr Król, Sidney H. Goodman, Edward M. Petrie, Endre Jakab, Euzebiusz Dziwinski, Bozena Krol, Marianne Blazsó, Zsuzsanna Czégény, Hanna Dodiuk, C. P. Reghunadhan NairAbstract:This paper investigates the efficacy of varied (non-intumescent and intumescent) polymer-based surface coatings in providing fire protection to glass fibre-reinforced (GFR) epoxy composites exposed to onesided radiant heating. In addition to an intumescent surface coating, two other non-intumescent surface coatings are considered - one that is active in the condensed phase and promotes surface char formation and another that is active in the gaseous phase and inhibits flaming combustion. The fire resistance of surface-coated GFR epoxy composite laminates is evaluated using the cone calorimeter at incident heat fluxes of 25, 50 and 65 kW/m2. For all tests conditions considered, there is a significant improvement in the fire performance of surface-protected GFR epoxy laminates relative to their unprotected counterparts. The intumescent surface-coated laminate showed the most significant variations in fire reaction properties with changes in irradiance. ?? 2012 Elsevier Ltd. All rights reserved.
Dejan D. Andjelkovic - One of the best experts on this subject based on the ideXlab platform.
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Novel Thermosets prepared by cationic copolymerization of various vegetable oils- : synthesis and their structure-property relationships
Polymer, 2005Co-Authors: Dejan D. Andjelkovic, Marlen Valverde, Phillip Henna, Fengkui Li, Richard C. LarockAbstract:A range of Thermoset Plastics have been prepared by the cationic copolymerization of olive, peanut, sesame, canola, corn, soybean, grapeseed, sunflower, low saturation soy, safflower, walnut, and linseed oils with divinylbenzene or a combination of styrene and divinylbenzene comonomers catalyzed by boron trifluoride diethyl etherate. The chemical, physical, thermal, and mechanical properties of these new polymers have been investigated as a function of the vegetable oil composition. The vegetable oil reactivity has a direct effect on most of the polymers' properties, which can be reasonably predicted by careful choice of the vegetable oil. Coupled with variations in the comonomer and stoichiometry, the choice of vegetable oil allows one to tailor the polymer's properties for specific applications.
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Novel Thermosets prepared by cationic copolymerization of various vegetable oils - Synthesis and their structure-property relationships
Polymer, 2005Co-Authors: Dejan D. Andjelkovic, Marlen Valverde, Phillip Henna, Fengkui Li, Richard C. LarockAbstract:A range of Thermoset Plastics have been prepared by the cationic copolymerization of olive, peanut, sesame, canola, corn, soybean, grapeseed, sunflower, low saturation soy, safflower, walnut, and linseed oils with divinylbenzene or a combination of styrene and divinylbenzene comonomers catalyzed by boron trifluoride diethyl etherate. The chemical, physical, thermal, and mechanical properties of these new polymers have been investigated as a function of the vegetable oil composition. The vegetable oil reactivity has a direct effect on most of the polymers' properties, which can be reasonably predicted by careful choice of the vegetable oil. Coupled with variations in the comonomer and stoichiometry, the choice of vegetable oil allows one to tailor the polymer's properties for specific applications. © 2005 Elsevier Ltd. All rights reserved.
