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941.
942.
943.
G. Merle J. P. Pascault Q. T. Pham C. Pillot R. Salle J. Gol I. Rashkov I. Panayotov D. Gurard A. Hrold 《Journal of polymer science. Part A, Polymer chemistry》1977,15(9):2067-2074
In the present work, we use the binary insertion compound LiC12 to polymerize styrene, methyl methacrylate, butadiene, isoprene, and to copolymerize isoprene and styrene in various hydrocarbon solvents (aromatics and aliphatic) and etheral solvents. We show that the styrene polymerization in aromatic solvents gives better yields than in the etheral solvents, the polymer being atactic. Methyl methacrylate does not polymerize in toluene but does so completely in DME. More generally, the yields of polymerization are better with KC37 than with LiC12 because of the different capacities of the monomer to get into the carbon layers. The polymerization of dienes with LiC12 shows that the microstructures of the polymer obtained in π-or n-donor solvents are similar to the ones obtained by homogenous polymerization with Li cation in such solvents. However, for isoprene in cyclohexane, the results are different. The isoprene styrene copolymers are statistical ones and the mean length of styrene blocks is less than 5. The monomer interaction with the insertion compound and the growing chain geometry between the carbon layers are the facts which control either the stereospecificity of the polymerization or the selectivity of the copolymerization. 相似文献
944.
945.
S. A. Giller A. V. Eremeev I. Ya. Kalvin'sh É. É. Liepin'sh V. G. Semenikhina 《Chemistry of Heterocyclic Compounds》1975,11(12):1378-1382
The reaction of 1,1-dimethylhydrazine with acrylic acid derivatives gave a number of 1,1-dimethyl-2-(2-substituted ethyl)hydrazines, which were quaternized by alkylating agents. The transformations of 1,1,1-trimethyl-2-(2-substituted ethyl)hydrazinium salts in the presence of sodium methoxide were investigated. 2-Cyano-, 2-carbomethoxy-, 2-carbethoxy-, and 2-carbodiethylamidoaziridines and a number of products of decomposition of the starting salts were obtained. 相似文献
946.
947.
948.
Conclusions The complexes of Co, Ni, Fe, and Cu with dimethyl- and diphenylglyoxime inhibit the initiated oxidation of cumene by reacting with the peroxide radicals.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1342–1344, June, 1971. 相似文献
949.
950.
Analysis of K-shell excitation spectra of gas-phase molecules containing at least two atoms of either B, C. N. O or F reveals the existence of a striking correlation between the bond length of the atomic pair. the sum of their atomic numbers and the associated α-shape resonance energy. Empirical rules are established which allow the derivation of intramolecular distances with accuracies reliably better than ± 0.05 A from the K-.shell absorption spectrum of one of the atoms in the Molecule. 相似文献