共查询到20条相似文献,搜索用时 15 毫秒
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S. P. Abramov A. A. Trofimova V. G. Barabanov 《Russian Journal of Applied Chemistry》2009,82(12):2187-2191
The applicability of Fourier IR spectroscopy to determination of the content of sulfonyl fluoride groups in the copolymer
of tetrafluoroethylene with perfluoro(3,6-dioxa-4-methyl-7-octene)sulfonyl fluoride (F-4SF copolymer) was examined. A procedure
was suggested for determination of sulfonyl fluoride groups, based on a correlation between the analytical signals in the
IR absorption spectrum of F-4SF and the sulfur content in F-4SF samples. 相似文献
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V. A. Lukyanova T. S. Papina 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2013,87(2):340-341
The energies of combustion of perfluoro(2-methyl-3-oxa)hexanoic and perfluoro(2,5-dimethyl-3,6-dioxa)nonanoic acids are for the first time measured in a calorimeter with a rotating platinized bomb and used to calculate the standard enthalpies of formation of these compounds in the liquid state. Based on the enthalpies of formation, the contribution from the [-CF2OCF(CF3)-] group to the enthalpies of formation of perfluoro acids is calculated. 相似文献
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Brian H Thomas 《Journal of fluorine chemistry》2004,125(8):1231-1240
A new type of ion exchange polymer, bis[(perfluoroalkyl)sulfonyl]imide ionomers (PFSI), were developed by the copolymerization of sodium 3,6-dioxa-Δ7-4-trifluoromethyl perfluorooctyl trifluoromethyl sulfonimide with tetrafluoroethylene (TFE) using an aqueous redox initiation system in an emulsion type polymerization. These polymers have been prepared in various equivalent weights and processed into functional membranes. The new ionomers exhibit excellent chemical and thermal stability. The materials have high potential for electrochemical applications especially as solid polymer electrolytes (SPE) in proton exchange membrane (PEM) fuel cells. 相似文献
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Conclusions On the basis of the EPR spectrum of perfluoro(4-methyl-2-pentene) (PMP) that has been exposed to gamma radiation at 77–300 K, three types of long-lived radicals have been observed, with lifetimes greater than two years. With increases in the radiolysis temperature for radiation dose, the concentration of long-lived radicals increases. Their relative concentrations depend on the irradiation conditions and the thawing schedule.Under certain conditions, long-lived radicals of a single type can be obtained from the PMP.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1263–1268, June, 1988. 相似文献
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在乙烯-四氟乙烯溶液共聚合体系研究中,我们曾编制了一个简易的计算机程序,用于测定二种单体的共聚竞聚率,这一方法计算方便,而且可以避免原先作图法中的误差,结果较为可靠。前文我们报道了四氟乙烯与两个新的全氟烷基乙烯基醚的共聚合反应,并对其中一个新单体——7,7-二氯-3-氧杂-全氟庚烯-1——与四氟乙烯的共聚进行了单体竞聚率的测定。结果表明,这一新的含氟烯醚单体的聚合活性较其它已有报道的同类单体大。为了验证这一 相似文献
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Tomoji Hikita Yoneho Tabata Keichi Oshima Kenkichi Ishigure 《Journal of polymer science. Part A, Polymer chemistry》1972,10(10):2941-2949
Radiation-induced copolymerization of tetrafluoroethylene with various vinyl ethers has been studied. It was found that tetrafluoroethylene can be copolymerized with vinyl ethers to give alternating copolymers over a wide range of the initial monomer concentration in the monomer mixture. The monomer reactivity ratios were determined for the copolymerization of tetrafluoroethylene with n-butyl vinyl ether as 0.005 (rTFE) and 0.0015 (rNBVE). The rate of copolymerization is extremely high and has a maximum at an equimolar concentration of two monomers. The alternating structure of the copolymers was confirmed by the analysis of NMR spectra. Some thermal properties of the copolymers were measured by DSC and DTA. 相似文献
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I. K. Kozlova 《Chemistry of Heterocyclic Compounds》1985,21(7):750-753
Some acylated o-amino-7-hydroxycoumarins have been obtained which may be used as intermediates in the preparation of fluorogenic substrates for certain enzymes.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 906–909, July, 1985. 相似文献
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É. V. Ganin Yu. A. Simonov A. A. Dvorkin G. S. Musienko G. G. Shagas T. I. Malinovskii 《Chemistry of Heterocyclic Compounds》1992,28(3):331-335
The reaction of 3,6-dioxa-1,8-(di-2,3-dichloromaleimido)octane with 3,6-dioxaoctane-1,8-diamine gave 7,11-diaza-1,4-dioxa-9-en-7,11-oxo-9-chlorobicyclo-[1.2.9]tridecan-8-one. The steric structure of the last was determined by x-ray structural investigation.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 394–398, March, 1992. 相似文献
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Wasaburo Kawai 《Journal of polymer science. Part A, Polymer chemistry》1968,6(1):137-146
A new monomer, 4-methyl-1,3-dioxene-4 was synthesized from allyl chloride and paraformaldehyde. The monomer was polymerized at room temperature or ?78°C. by boron trifluoride etherate catalyst, and the structure of the obtained polymer was determined by infrared, nuclear magnetic resonance spectra, and chemical analysis. It was ascertained that the polymerization process proceeded through a ring-opening mechanism at the dioxane ring. In the presence of tetrahydrofuran, the polymerization of 4-methyl-1–1,3-dioxene-4 led to copolymer. The mechanism of the copolymerization is described in detail. 相似文献
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Karaböcek Serdar Değirmencioğlu İsmail Karaböcek Nevin Serbest Kerim 《Transition Metal Chemistry》2003,28(5):529-533
1,9-Dioxa-3,6-dithiacyclotridecane-10,12-dione (L1), and 1,4-dioxa-7,10-dithiacyclododecane-2,3-dione, (L2), two novel ligands, and their mono- and di-nuclear copper(II) and/or nickel(II) complexes have been prepared and characterized by elemental analyses, 1H- and 13C-n.m.r., i.r., magnetic moments and mass spectral studies. Elemental analyses, stochiometric and spectroscopic data on the complexes indicate that the metal ions are coordinated to the nitrogen, oxygen and sulphur atoms and the data support the proposed structure for the diones and their mono–dinuclear copper(II) complexes. Moreover, copper(II) complexes of the dione ligands have a 1:1 metal:ligand ratio. 相似文献
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G. G. Furin A. P. Krysin N. I. Protsuk V. A. Lopyrev 《Russian Journal of Organic Chemistry》2006,42(10):1429-1434
Reactions of perfluoro(2-methylpent-2-ene) and perfluoro(5-azanon-4-ene) with 4-(2-aminoethyl)-2,6-di-tert-butylphenol and 4-(3-aminopropyl)-2,6-di-tert-butylphenol in acetonitrile in the presence of triethylamine gave the corresponding azetidine, 1,2-dihydroazete, and 1,2-dihydro-1,3-diazete derivatives, respectively. The reaction mechanisms, role of triethylamine, and factors affecting the intramolecular nucleophilic cyclization process are discussed. 相似文献
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A. A. Korlyukov M. G. Voronkov É. A. Zelbst E. A. Grebneva O. M. Trofimova M. Yu. Antipin 《Journal of Structural Chemistry》2008,49(4):732-736
The molecular structure of 1-methyl-1-fluoroquasisilatrane (2-methyl-2-fluoro-1,3-dioxa-6-aza-2-silacyclooctane) MeFSi(OCH2CH2)2NH (I) is determined by single crystal X-ray diffraction at 100 K. The coordination polyhedron of the silicon atom in this molecule is a slightly distorted trigonal bipyramid with an NH group and a strongly electron-withdrawing fluorine atom in the axial positions, and two endocyclic oxygen atoms and a CH3 group in three vertices of the equatorial plane. The axial angle N→SiF is 171°. The length of the transannular donor-acceptor bond N→Si (2.058 Å) is as small as in 1-fluorosilatrane. The axial bond F-Si (1.660 Å) is longer than that in 1-fluorosilatrane and tetrahedral silicon compounds. 相似文献
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Fikry M. Mikhail Pakinam Askalani John Burgess Robert Sherry 《Transition Metal Chemistry》1981,6(1):51-54
Summary Kinetic parameters are reported for aquation of the tris-(4-methyl-1,10-phenanthroline) iron(II) [Fe(4-Mephen)3]2+, cation and for its reactions with hydroxide, cyanide, and peroxodisulphate. Activation volumes have been determined for the two last-named reactions; they reflect the importance of solvation changes in transition state formation. 相似文献
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The thermal decomposition of the title compound has been studied in the gas phase in the temperature range of 584–634 K. The decomposition was found to be a first-order homogeneous process yielding 2-methylbuta-1,3-diene and formaldehyde. The rate constants obtained at 11 temperatures within the quoted range fitted the Arrhenius equation The decomposition is probably unimolecular and concerted. 相似文献