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Fine Chemical Technologies

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Vol 11, No 3 (2016)
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https://doi.org/10.32362/2410-6593-2016-11-3

CHEMISTRY AND TECHNOLOGY OF ORGANIC SUBSTANCES

5-11 129
Abstract
It is known that coatings produced by electrodeposition, cured at high temperatures (180ºC and above).The aim of this study is reducing the energy intensity of production of polymer coatings, improving physical, mechanical properties of the polymer coatings and expansion of colors of paints for the electrodeposition. As the object of study was chosen lacquer KCh-0125, the main component of which is maleated polybutadiene. A micelle of film-forming neutralized tertiary amine is a colloidal particle size of 40 to 70 nm. One of the most effective and lowcost ways to the above problems is the introduction of the water-based oligomeric compositions hydrophobic modifiers. As modifiers were selected naturally occurring metalloporphyrins - cobalt (II) complex of pheophytin a (СоPh) and copper (II) complex of methylpheophorbide a (CuMPP). The method of introduction of the СоPh and the CuMPP of the water-based compositions for electrodeposition was developed. Colloid-chemical properties of the resulting compositions were studied. It was presented the most probable structure of the scheme colloidal particles modified by metalloporphyrins. It was conducted viscometric, spectral studies; the method of dynamic light scattering was used to determine the zeta potential and the size of colloidal particles. It was demonstrated high catalytic activity of metal complexes of porphyrins examined in structuring processes electrodeposited coatings when cured. Introduction of metalloporphyrins in the coating helps to reduce the curing temperature to 160°C. This makes it possible to reduce or duration, or a temperature curing coatings. The introduction of CuMPP make possible to obtain transparent coatings emerald green. Modified electrodeposited coatings also have good water and salt resistance.
12-16 106
Abstract
Preparative gas chromatography is proposed to isolate some high-boiling organometallic compounds. Isolation of high-boiling substances should be conducted at a column temperature significantly below the boiling point, because most isolated compounds are thermally unstable at such temperatures. Stationary phases for preparative gas chromatography have a temperature limit of 350°C. The reduction of the column temperature is based on simultaneous changing the parameters of the chromatographic experiment (column length, impregnation degree, flow rate of the carrier gas). The influence of reducing the column temperature on the shape of the chromatographic peak is shown. The peak has an asymmetric shape, and its width increases. Therefore, the possibility of high-boiling substances preparative isolation depends on temperature decrease as the column separation efficiency is maintained.

THEORETICAL BASES OF CHEMICAL TECHNOLOGY

17-30 130
Abstract
In order to explain the time-temperature dependence of the electrical resistance of HDPE filled with carbon black, a model is proposed, in which an important role is played by the interfacial layer between the solid-phase filler and the polymer matrix. It is shown that the change in the structure of the macromolecules in the interfacial layer can be characterized using fractal concepts. The fractal dimension increases as the size of the filler particles decreases, and this is accompanied by a decrease in electrical resistance. During isothermal annealing treatment of the samples the fractal dimension of the interfacial layer is changed from 2.3 to 3. Correlations of the observed parameters are presented. The activation energy of increasing resistance in the initial period of the sample treatments is calculated. It is shown that the electrostatic field restrains the increase of the fractal dimension of the interfacial layer and the change in the resistance of the filled systems.
31-38 120
Abstract
The temperature dependence of EPR spectrum of 2,5-bis(trifluoromethyl)nitrobenzene radical anion in anhydrous DMF was investigated. Internal dynamics of hindered rotation of the CF3-group in ortho-position to NO2-group causes HFS modulation. The spectrum changes are reversible and temperature-dependent. An original temperature-activation representation of complex spectral density was proposed instead of the traditional spectral-kinetics representation to explain the observed transformation. The change resulted in a new convenient phenomenological reconstruction model, which allowed simulating the spectra in the whole temperature range. Splitting constants and contributions to the spectral widths of the spectral lines were found. The activation energy of the CF3-group hindered rotation is significant and amounts to 37 kJ/mol.
39-46 127
Abstract
A significant part of the gross domestic product is lost because of hitches followed by long downtime periods in industrial systems. This is a common problem in the industry of developed nations. Analysis of causes of this phenomenon allows developing a conception of solving this problem and suggesting a method of studying the reliability (working capacity) of chemical-engineering systems (CES). In this article we prove the need for technological reliability analysis tools in prefeasibility study to estimate the potential working capacity of the technology and to avoid the large costs of starts and stops.
47-57 124
Abstract
An approach to the determination of free variables required for calculating the material balance of the flowsheet of ternary mixtures separation is presented. Phase diagrams of the considered ternary systems are characterized by the presence of a two-phase splitting area and by the presence of different amounts of azeotropes (classes 3.1.0, 3.1.1, 3.2.1 and 3.3.1). For all the systems flowsheets containing three rectification columns and a florentine vessel for separation were suggested. The multivariance of the solution of the balance problem was shown. The approach was illustrated by the example of real ternary systems characterized by different phase diagrams (methanol - chloroform - water, butyl alcohol - water - toluene, nitromethane - hexane - water). The parameters of the rectification columns were presented.

CHEMISTRY AND TECHNOLOGY OF MEDICINAL COMPOUNDS AND BIOLOGICALLY ACTIVE SUBSTANCES

58-63 115
Abstract
Spray-dried forms of anthocyanins were prepared in a maltodextrin matrix. The anthocyanins were extracted by maceration of elderberry fruits in 0.1 M HCl followed by extract filtration through a paper filter. The extract was partially purified by solid phase extraction in a column filled with styrene-divinylbenzene copolymer beads (Sepabeads SP859/L) or in syringe cartridges with C18 silica (BioChemMack ST, Moscow, RF) followed by re-extraction with aqueous HCl and alcohol mixtures. The procedure of reversed-phase HPLC determination of the extracted anthocyanin type is discussed in comparison to HILIC method in DIOL silica columns. The latter method was shown to be preferable to avoid systematic errors in the anthocyanin type determination. Solidphase extraction in syringe cartridges gave samples with very high anthocyanins concentration (up to 70 g of cyanidin-3-glucoside chloride equivalent). When using the copolymer sorbent, the concentration was somewhat lower: up to 27 g/l. After spray drying red powder samples with anthocyanins content more than 2% were prepared, although freeze drying gave only dark resin. The red color of the samples indicates the space separation of flavylium ions in the solid state by radicals of the maltodextrin background.
64-73 157
Abstract
The effect of anionic phospholipids, namely, cardiolipin, phosphatidylglycerol and phosphatidic acid, on the growth of gram-negative bacteria E. coli BL21(DE3), as well as gram-positive bacteria M. tuberculosis H37Rv was investigated in this study. The influence of all anionic phospholipids tested on the bacteria growth was shown to be dose-dependent. Lipids at concentrations below 335 μM didn’t affect, while at 335 μM and above they repressed bacteria growth and caused cellular death of both type of microorganisms. SOS response induction was observed by using strain E. coli CSH50 sfiA::lacZ during cultivation E. coli with cardiolipin, phosphatidylglycerol and phosphatidic acid. This indicates DNA damage through double-strand breaks. One reason of the DNA damage could be stabilization of transient complexes of DNA topoisomerase (types I and II) with DNA temporary broken by anionic phospholipids. However, neither phosphatidylglycerol nor phosphatidic acid affect the activity of types I and II DNA topoisomerases from E. coli in vitro. In contrast, cardiolipin inhibited DNA topoisomerase I and DNA gyrase (type II topoisomerase), but didn’t stabilize transient complexes of the enzyme with DNA. It indicates that DNA damage due to anionic phospholipids exposure didn’t result from inhibition of DNA topoisomerase activity through stabilization of the transient complex of the enzyme with DNA. The obtained results of cardiolipin, phosphatidylglycerol and phosphatidic acid bactericidal activity against grampositive M. tuberculosis and gram-negative E. coli make it possible to use anionic phospholipids as individual antimicrobial agents or as a matrix of effective and non-toxic liposomal drugs for tuberculosis treatment.

CHEMISTRY AND TECHNOLOGY OF INORGANIC MATERIALS

74-81 133
Abstract
Three technologies of nickel-oxide cathodes based on nickel powder and on barium-calciumstrontium triple carbonate powder for microwave ovens of the centimetric wave length range devices are suggested. The optimum fraction of nickel powder for the production of cathodes is 45-71 microns. The optimum content of the triple carbonate is 10%. The optimum pressure of pressing is 7 t/cm2. The optimum temperature of agglomeration is 1100°C for 10 min. The quality improvement and yield of suitable cathodes are provided by the use of agglomerates of nickel and triple carbonates. The agglomerates contain nickel particles of the 10-25 microns fraction coated with the triple carbonate containing 50% of the carbonate and baked in dried hydrogen at 1000°C for 10 min. The formation of the cathode is carried out by mixing and agglomerating the 45-63 microns fraction and the nickel 45-71 microns fraction with the carbonates concentration 10%. In order to improve the cathodes quality it is expedient to anneal the agglomerates after their production in carbon dioxide at 200-300°C with a final purge by nitrogen at 1000°C for 10 minutes. The use of agglomerates based on nickel and the triple carbonate for the production of oxide-nickel cathodes provides more uniform distribution of the emission-active agent in the volume and on the surface of the cathodes.
82-85 223
Abstract
The article is dedicated to the memorable tragic date - to the 75th anniversary of the beginning of the Great Patriotic War of 1941-1945 and to the activity of the Lomonosov Moscow Institute of Fine Chemical Technology in 1941-1942: mobilization, evacuation, renewal of the educational and scientific activity in the conditions of the martial law.


ISSN 2410-6593 (Print)
ISSN 2686-7575 (Online)