Copolymerization of N-allenylimidazole with di(ethylene glycol) divinyl ether and complexation of the copolymers with CuCl2

Polyfunctionalized linear copolymers of N-allenylimidazole and di(ethylene glycol) divinyl ether with polyconjugated (polyvinylene) blocks in the main chain and exomethylene bonds and vinyloxyethoxyethyl groups in the side chain were prepared. Using the reaction of the copolymers with CuCl₂, a possibility of synthesis of polymeric metal complexes for catalysis of organic reactions was shown. The IR and ESR spectra of the complexes were studied. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 973–977, June, 2006.     

Aqueous polymerization of acrylonitrile initiated by the bromate–thiourea redox system

The aqueous polymerization of acrylonitrile initiated by an acidified bromate–thiourea redox system has been studied under nitrogen atmosphere. The rate of polymerization is independent of thiourea concentration over the range 2–9 × 10^?3M and reaches maximum at 9 × 10^?3M. The rate varies linearly with [monomer]. The initial rate of polymerization as well as the maximum conversion increases within the range of 4–22.5 × 10^?3M KBrO₃, but beyond 22.5 × 10^?3M the rate of polymerization decreases. The initial rate and the limiting conversion increases with increasing polymerization temperature in the range 30–45°C; and beyond 45°C they decrease. The effect of certain neutral salts, water-soluble solvents, and micelles of cationic, anionic, and nonionic surfactants on the rate of polymerization has been investigated.     

On the relationship between the length of an algebra and the index of nilpotency of its Jacobson radical

A sharp upper bound for the length of an algebra as a function of the index of nilpotency of its Jacobson radical and the length of the quotient algebra by the radical is obtained.     

Grafting Vinyl Monomers onto Wool Fibers. VII. Graft Copolymerization of Methyl Methacrylate onto Wool Using Peroxydiphosphate-Thiourea Redox System

Graft copolymerization of methyl methacrylate onto wool was investigated in aqueous solution using the potassium peroxy-diphosphate-thiourea redox system as the initiator. The rate of grafting was determined by varying the monomer, peroxydi-phosphate ion, temperature, and solvent. The graft yield increases with increasing peroxydiphosphate ion up to 80 × 10^?-⁴ mol/L, and with further increase of peroxydiphosphate ion the graft yield decreases. The graft yield increases with increasing monomer concentration. The percentage of grafting decreases with increasing thiourea concentration. The rate of grafting increases with an increase of temperature. The effect of acid and water-soluble solvent and certain salts on graft yield has been investigated and a suitable rate expression has been derived.     

Expedient Strategy for the Synthesis of 5-Acylethynylpyrrole-2-carbaldehydes

5-Acylethynylpyrrole-2-carbaldehydes have been synthesized from the protected pyrrole-2-carbaldehydes by their transition-metal-free topochemical mechanoactivated ethynylation with acylbromoacetylenes in a solid Al₂O₃ medium (room temperature, 6 h, 41–54% yields).     

Nanofibers prepared by electrospinning from solutions of biobased polyamide 4

A successful preparation of polyamide 4 nanofibers via electrostatic spinning with diameters close to 100 nm is described. Polyamide 4 was prepared by the anionic ring‐opening polymerization of 2‐pyrrolidone and characterized. The effect of the system parameters (i.e., molar mass of the polymer, the solvent system) and the process parameters (i.e., the electrode‐to‐collector distance) during the electrostatic spinning have been studied. The morphology of the polyamide 4 fiber layers is given except molar mass of the polymer and the concentration of its solution primarily by the conformation of polyamide chains due to polyelectrolyte effect which was confirmed by viscosity measurements. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55, 2203–2210     

First geochemical data on loose sediments in the Kan-i-Gut cave mine (Central Asia) by synchrotron radiation XRF analysis

The elemental composition of loose sediments in the Kan-i-Gut cave mine located in the foothills of the Turkestan range (Kyrgyzstan) is determined by X-ray fluorescence analysis with the use of synchrotron radiation. The samples of loose sediments are selected at different points in the cave, from the entrance to the lowest horizon. The first geochemical data on residual loose sediments in the Kan-i-Gut cave mine are obtained. They allow detailed study of the poorly studied migration of chemical elements in karstic cavities and its specific conditions, which can remain unchanged for a long time.     

Novel oligo-m-carboranylenemethylenesilanes

A method has been developed for the obtaining of new oligo(dimethyl)silanes comprising 1,7-bis(methyl)-m-carboranyl units and bearing the terminal chlorosilyl or methoxysilyl groups. Reactions of such oligomers with an excess of benzylmagnesium chloride or 1-chloromagnesiummethyl-m-carborane lead to oligo-m-carboranylenemethylenesilanes containing the terminal benzylsilyl or m-carboranylmethylenesilyl groups. The novel oligomers are highly viscous liquids possessing a high heat resistance and also a resistance towards the treatment with a strong alkaline reagent.