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Yonggang Yang - One of the best experts on this subject based on the ideXlab platform.
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a mechanism study on preparation of rayon based carbon fibers with nh4 2so4 nh4cl Organosilicon composite catalyst system
Composites Science and Technology, 2007Co-Authors: Hui Li, Yonggang YangAbstract:Abstract The mechanisms of the preparation of rayon based carbon fibers with (NH 4 ) 2 SO 4 /NH 4 Cl/Organosilicon composite catalyst system were studied. The thermal behaviors of rayon fibers that were treated with different catalysts were studied by thermogravimetry–mass spectrometry (TG–MS) and the surface of treated rayon fibers was studied by scanning electron microscopy (SEM) analysis. Our data showed that the composite catalyst treated rayon fibers underwent pyrolysis under lower temperatures and in a wider range of temperatures. Rayon based carbon fibers prepared with different catalyst system showed different mechanical properties. The presence of (NH 4 ) 2 SO 4 /NH 4 Cl/Organosilicon increased the production of H 2 O, CO 2 , CO and decreased the production of tar, aldehyde, furan and phenol derivatives. The composite catalyst also promoted the pyrolysis reaction of rayon fibers by lowering its activation energy. Organosilicon seemed to have two aspects of effects on the process of preparing rayon based carbon fibers. It could enhance the penetrability of (NH 4 ) 2 SO 4 /NH 4 Cl to the interior of rayon fibers and protect the fiber surface in the pyrolysis process. Moreover, Organosilicon may participate in the crosslinking reactions of rayon fibers and enhance the drawability of rayon fibers in carbonization process. Our experiments demonstrated that (NH 4 ) 2 SO 4 /NH 4 Cl/Organosilicon was an effective composite catalyst system in the preparation of rayon based carbon fibers.
M. G. Voronkov - One of the best experts on this subject based on the ideXlab platform.
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Et_3GeN(SiMe_3)_2 and Et_3SnN(SiMe_3)_2: New precursors for chemical vapor deposition processes
Inorganic Materials, 2013Co-Authors: S. V. Sysoev, L. D. Nikulina, E. N. Ermakova, M. L. Kosinova, V. I. Rakhlin, I. P. Tsyrendorzhieva, A. V. Lis, M. G. VoronkovAbstract:We have synthesized the germanium- and tin-containing Organosilicon compounds Et_3GeN(SiMe_3)_2 and Et_3SnN(SiMe_3)_2 as new precursors for the preparation of materials by chemical vapor deposition. The compounds were characterized by NMR, IR and UV spectroscopies and thermal analysis. Using vapor pressure measurements, we obtained temperature dependences of their saturated vapor pressure. We assessed their thermal stability and calculated the thermodynamic characteristics of vaporization of the Organosilicon compounds.
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An Organosilicon Sorbent with Dithiocarbamate Groups
Doklady Chemistry, 2004Co-Authors: Yu. N. Pozhidaev, E. N. Oborina, L. I. Belousova, N. N. Vlasova, M. G. VoronkovAbstract:Organic derivatives of dithiocarbamates are findingextensive practical use. Many of them possess specificbiological activities and are recommended as medicinaldrugs [1, 2]. An important field of practical applicationof organic compounds containing dithiocarbamategroups is their use as reagents to determine heavy metalions [3–5] and to purify wastewaters from toxic con-taminants [6, 7]. Sorbents with dithiocarbamate groupshave been reported [8, 9].While developing the research into carbofunction-ally substituted Organosilicon monomers and materialsfor sorption based on them [10, 11], we synthesized andstudied an Organosilicon sorbent containing dithiocar-bamate groups.The initial monomer, 3-triethoxysilylpropylammo-nium 3-triethoxysilylpropyldithiocarbamate (
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Thermochemistry of Organosilicon compounds. I. Triorganyl-, tetraorganyl-, organylorganoxy- and tetraorganoxy-silanes.
Journal of Organometallic Chemistry, 1991Co-Authors: M. G. Voronkov, V. P. Baryshok, V.a. Klyuchnikov, T. F. Danilova, V.i. Pepekin, A. N. Korchagina, Yu.i. KhudobinAbstract:Abstract A technique for the controlled combustion of liquid and solid Organosilicon compounds has been developed. Seventy-two tetracoordinate silicon compounds: triorganyl-, tetraorganyl-, organylorganoxy- and tetraorganoxysilanes have been investigated thermochemically. Their combustion and sublimation, or evaporation, enthalpies have been determined. Formation enthalpies of the compounds concerned in the condensed and gaseous states, and their atomization enthalpies in the gas phase have been calculated. The magnitudes of the fragments for an additive scheme of calculation of atomization enthalpies and bond energies in Organosilicon compounds of the above type have been determined.
Hui Li - One of the best experts on this subject based on the ideXlab platform.
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a mechanism study on preparation of rayon based carbon fibers with nh4 2so4 nh4cl Organosilicon composite catalyst system
Composites Science and Technology, 2007Co-Authors: Hui Li, Yonggang YangAbstract:Abstract The mechanisms of the preparation of rayon based carbon fibers with (NH 4 ) 2 SO 4 /NH 4 Cl/Organosilicon composite catalyst system were studied. The thermal behaviors of rayon fibers that were treated with different catalysts were studied by thermogravimetry–mass spectrometry (TG–MS) and the surface of treated rayon fibers was studied by scanning electron microscopy (SEM) analysis. Our data showed that the composite catalyst treated rayon fibers underwent pyrolysis under lower temperatures and in a wider range of temperatures. Rayon based carbon fibers prepared with different catalyst system showed different mechanical properties. The presence of (NH 4 ) 2 SO 4 /NH 4 Cl/Organosilicon increased the production of H 2 O, CO 2 , CO and decreased the production of tar, aldehyde, furan and phenol derivatives. The composite catalyst also promoted the pyrolysis reaction of rayon fibers by lowering its activation energy. Organosilicon seemed to have two aspects of effects on the process of preparing rayon based carbon fibers. It could enhance the penetrability of (NH 4 ) 2 SO 4 /NH 4 Cl to the interior of rayon fibers and protect the fiber surface in the pyrolysis process. Moreover, Organosilicon may participate in the crosslinking reactions of rayon fibers and enhance the drawability of rayon fibers in carbonization process. Our experiments demonstrated that (NH 4 ) 2 SO 4 /NH 4 Cl/Organosilicon was an effective composite catalyst system in the preparation of rayon based carbon fibers.
A. M. Muzafarov - One of the best experts on this subject based on the ideXlab platform.
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Behavior of Organosilicon Surfactants in Langmuir Films on the Surface of Water
Polymer Science Series A, 2019Co-Authors: A. A. Ezhova, I. A. Gritskova, A. E. Chalykh, S. M. Levachev, D. I. Shragin, S. N. Chvalun, Yu. N. Malakhova, A. M. MuzafarovAbstract:The behavior of Organosilicon surfactants of different structure in model systems—Langmuir films—at the water/air interface is studied. It is shown that, under the compression of Langmuir films, the conformational states of surfactants of different structure are different. The obtained data make it possible to explain a high stability of polymer suspensions synthesized in the presence of Organosilicon surfactants.
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the influence of an Organosilicon modifier on the properties of a compound based on epoxy urethane oligomer
Polymer Science. Series D, 2017Co-Authors: O I Sidorov, D. I. Shragin, A. M. Muzafarov, S A Kapustin, N I Sidorova, D V PleshakovAbstract:To improve the performance characteristics of products made of highly-filled polymer compositions, modification of a compound based on epoxy-urethane oligomer was performed. The SH 198 amino functional Organosilicon oligomer was used as a modifier. The performed studies established that an Organosilicon modifier increases the gel time and the curing time of the composition based on epoxy-urethane oligomer, shows the plasticizing effect on a compound, decreases its glass transition temperature from 16.5 to 9°C, and increases the deformation in the temperature range of from–40 to +50°C.
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Organosilicon compounds in supercritical carbon dioxide: Synthesis, polymerization, modification, and production of new materials
Polymer Science Series B, 2016Co-Authors: M. A. Pigaleva, I. V. Elmanovich, M. N. Temnikov, M. O. Gallyamov, A. M. MuzafarovAbstract:The main promising opportunities for the advantageous combination of Organosilicon compounds and supercritical carbon dioxide both as a solvent and as a reagent in chemical processes are analyzed. The main processes of polymerization and modification of polymer matrices that are performed in supercritical СО_2 with the use of Organosilicon materials of various types are outlined. Methods for the obtaining Organosilicon polymers and polymer-inorganic composites and methods for the application of siloxane stabilizers in the dispersion polymerization of monomers in supercritical СО_2 are described. Studies of the insertion of a СО_2 molecule into Si–H, Si–N, and Si–O–Me bonds in reactions that feature exceptionally high chemical selectivity and afford a wide spectrum of products potentially useful for application in the chemistry of polymer materials are considered. It is shown that the silylation of surfaces of various types and morphologies in the medium of supercritical СО_2 is a rapidly developing green approach that makes it possible to obtain highly uniform defect-free coatings with variable desired functionality.
Yunyun Liu - One of the best experts on this subject based on the ideXlab platform.
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Multicomponent Reactions Promoted by Organosilicon Reagents
Current Organic Chemistry, 2011Co-Authors: Jie-ping Wan, Yunyun LiuAbstract:Organosillicon reagents have been found as versatile catalysts or promoters for a broad range of organic reactions due to their special properties of multifunction. An important application of Organosilicon reagents is in the research field of multicomponent reac- tions (MCRs), which provides a vast number of practical synthesis for different molecular libraries. We present in this review the recent research progress of MCRs employing organosillicon reagents as catalysts or promoters for the first time.