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61.
以双[对-酰氯苯基]二甲基硅烷和酚酞、四溴酚酞以及双酚A为原料,合成了三种主链含硅聚芳酯,并对聚合物相关的物理性质进行了表征,制成了均质透明的薄膜.采用低真空法测定这些聚合物对H2、O2、N2、CO2、CH4的气体透过速率,并计算出气体透过系数、扩散系数、溶解系数、分离系数.从气体透过性能与聚合物分子结构关系的角度,按照气体透过的溶解-扩散机制,对聚合物的气体透过性能进行了研究,而且着重讨论了聚合物的堆积密度对气体扩散系数的影响,以及聚合物主链中极性链段的百分含量对气体溶解系数和溶解选择性的影响。 相似文献
62.
The polymerization rates of three cyanopyridines catalyzed by cuprous chloride-zinc system are measured, and the structure of the formed polymer is also determined. Compared with aromatic nitrile, cyanopyridines polymerize faster and form polyconjugated polymer with skeleton—(C=N)—_n instead of triazine structure. This chain-polymer possesses semiconductive property, and can be converted into conductive material by thermal treatment. In addition, the polymerization kinetics of 3-cyanopyridine catalyzed by 3-cyanopyridinium perchlorate is investigated. It is found that the polymerization rate is directly proportional to the concentrations of monomer and catalyst, and the activation energy of the polymerization is 103.1 KJ/mol. 相似文献
63.
The cyclic voltammetric behaviour of Eu3+/Eu2+ couple at hanging mercury drop electrode (HMDE) has been studied in chloride, bromide, iodide, thiocyanate and EDTA supporting
electrolytes. The apparent rate constant and transfer coefficient for these systems have been calculated at various voltage
scan rates, without using the data for standard or formal potential. The values have been compared with those obtained by
earlier workers through other electrochemical methods. 相似文献
64.
采用自制二胺1,2-二氢-2-(4-氨基苯基)-4-[4-(4-氨基苯氧基)-苯基]-二氮杂萘-1-酮、商品二胺4,4′-二氨基二苯甲烷和对苯二胺与对苯二甲酰氯进行低温溶液缩聚反应,改变三种二胺的比例,得到了一系列共聚酰胺树脂,其特性粘数为1·24~2·32dL/g,用FT-IR、1H-NMR手段研究了聚合物的结构;利用DSC和TGA研究了聚合物的耐热性能,结果表明,该类聚合物具有较高玻璃转化温度(301℃以上);氮气气氛中5%热失重温度在438℃以上;用一定比例的二胺制得的聚合物分别能溶于N-甲基吡咯烷酮、N,N-二甲基乙酰胺等非质子极性溶剂中并浇注得到韧性薄膜. 相似文献
65.
ODIN, a non-empirical INDO-MO scheme, has been used to determine the ground state electronic configurations for the tetrahedral molecules, VCl4 and VBr4. A 2
E ground state was obtained for both molecules. The Photoelectron spectrum and the electronic spectrum have been calculated for VCl4, and a satisfactory correlation with the corresponding experimental data was made. Also, ODIN was employed to evaluate electronic transition energies and the photoelectron spectrum of VBr4. 相似文献
66.
Summary The capabilities of sulfur hexafluoride as a mobile phase for supercritical-fluid chromatography are investigated. An evaluation
of its overall utility on the basis of separations of standard aromatic hydrocarbon odel mixtures performed on a variety of
bonded-phase, packed columns with UV detection is presented. The dependence of separation performance upon operational parameters
is also examined. A comparative evaluation of the chroamtographic properties of supercitrical sulfur hexafluoride and those
of supercritical carbon dioxide is developed from these separations under corresponding supercritical state conditions. 相似文献
67.
A. I. Ilovaisky V. M. Merkulova Yu. N. Ogibin G. I. Nikishin 《Russian Chemical Bulletin》2005,54(7):1585-1592
Electrolysis of salts of primary and secondary nitro compounds (nitroethane, 1- and 2-nitropropanes, nitrocyclohexane, and
nitrocycloheptane) in the presence of excess halide, nitrite, cyanide, and phenylsulfinate anions under undivided and divided
amperostatic electrolysis conditions in a two-phase medium (CH2Cl2/H2O) produces geminal nitrohalides (35–85% yields), dinitro compounds (15–51%), nitronitriles (6–27%), and nitrosulfones (50–70%).
The salts of secondary nitro compounds form the products of oxidative coupling with halide and phenylsulfinate anions under
the undivided electrolysis conditions. In all other cases, divided electrolysis is required.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1539–1546, July, 2005. 相似文献
68.
Mariusz Klobukowski 《Theoretical chemistry accounts》1992,83(3-4):239-248
Summary The effective core potential and model potential methods were used in post-SCF calculations on HC1, HBr, Cl2, and Br2 in order to gain insight into the effect of insufficient representation of inner nodes in the valence orbitals of the approximate methods. The results show that while the correlation energy may be slightly overestimated (by 1–7%), both the electric moment functions and the quantities depending on energy differences are consistently similar for the methods studied and close to the results from all-electron calculations.Dedicated to Prof. Klaus Ruedenberg 相似文献
69.
70.