Scientific Journal of KubSAU

Polythematic online scientific journal
of Kuban State Agrarian University
ISSN 1990-4665
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304 kb

INFLUENCE OF ORGANIC SOLVENTS ON WATER DISSOCIATION IN BIPOLAR MEMBRANE

abstract 1141510019 issue 114 pp. 261 – 274 30.12.2015 ru 1310
The article discusses results of experimental research of the influence of aprotic and proton solvents on reaction rate of water molecules dissociation in the bipolar membrane MB-1 by the method of electrochemical impedance frequency spectrum. It was discovered, that addition of organic component in aqueous solutions results in significant influence on the parameters of water dissociation in a bipolar region of the membrane. The reason for this influence is the reduction of the mass fraction of water in solution and, consequently, in a bipolar region of the membrane, which itself reduces the rate of the dissociation reaction. Another reason for the influence of the organic solvent is its effect on the network of hydrogen bonds existing in water and aqueous solutions. Depending on the nature of organic solvent and its concentration, the network of hydrogen bonds may be strengthened, or destroyed, thus facilitating removal of the proton involved in the reactions between water molecules and catalytic centers in cation-exchange and anion-exchange layer of bipolar membrane, or retarding removal of proton. This leads respectively to speed up or slow down the rate of dissociation in the bipolar region of the membrane, as well as changing the constants of the dissociation reaction of water. Introduction of organic solvent in solutions, which are in the contact with bipolar membrane, is a convenient method of investigating the role of solution composition on the rate of proton transfer between water molecules and catalytic centers in the membranes
1320 kb

INFLUENCE OF HEAVY METALS HYDROXIDES ON WATER DISSOCIATION IN BIPOLAR MEMBRANE

abstract 1141510020 issue 114 pp. 275 – 287 30.12.2015 ru 1020
The results of study of bipolar membrane – analogue of MB-2, modified with chemically introduced chromium (III), iron (III) and nickel (II) hydroxides by the method of frequency spectrum of electrochemical impedance, by infrared spectroscopy and scanning electron microscopy in combination with X-ray spectrum analysis are presented. It is shown, that sequential treatment of cation-exchanger, contained in cationexchange membrane, with metal salt solution and alkali solution does not result in formation of complex compounds of these metals with ionic groups of ion exchanger. It was found that in these conditions the presence of heavy metals in the phase of cationexchanger confirmed by X-ray analysis, however, crystals of hydroxides of heavy metals are not detected in the size range of 1000 nm to 20 nm. These heavy metal compounds are thermally unstable and their catalytic activity in the reaction of dissociation of water molecules decreases with increasing temperature during heat treatment. The introduction of low-soluble hydroxides of d-metals (chromium (III), iron (III), nickel(II)) by chemical method can significantly improve the electrochemical characteristics of a bipolar membrane. The most effective catalysts in water dissociation reaction are the hydroxides of chromium (III) and iron (III) and, as a consequence, membranes with these hydroxides have a lower value of overpotential compared with original membrane at the same current density
312 kb

THERMOREACTIVE OLIGOMERS FROM HEXAMETHYLENE-bis-MALEIMIDE and 5,5’- bis-BENZOTRIAZOLES, AND GLUED JOINTS ON BASE OF THEM

abstract 1141510035 issue 114 pp. 478 – 491 30.12.2015 ru 995
A number of thermoreactive oligomers was obtained via the Michael interaction of molar excesses of hexamethylene-bis-maleimide with 5,5’-bisbenzotriazoles in melt. The structure of them was proved by the 13C spectroscopy method. The one-step synthesis in melt, without by-products evolution, in absence of organic solvents, additional reagents, and catalysts is the more acceptable in point of view of technology (a finished reaction product does not require any purification). The process itself is the nucleophile addition across double bond, and so it can be attributed to the atom-saving technologies. According to data of the dynamic scanning calorimetry (DSC) and the thermogravimetry (TG), oligomers fuse at 130.8–135.6 °С, cross-link at 185–250 °С, and begin their thermal destruction in air at temperatures of 400– 420 °С. The tensile strength at shear of the glued joints on base of oligomers (steel plates overlapped) is 14.2– 23.7 MPa (142–237 kgf/cm2 ). The positive effect from the introduce of 5,5’-bis-benzotriazolyl fragments into structure of bismaleimide thermoreactive oligomers on strength of the glued joints between metal plates was revealed
126 kb

RESEARCH IN MICRODEFICIENCY OF POLYMERS (RUBBERS AND RUBBERIZED FABRICS) USING EXPRESS TECHNIQUE OF ASSESSMENT BY THE SORPTION AND WEIGHT METHOD

abstract 1181604048 issue 118 pp. 817 – 826 29.04.2016 ru 745
Macrodeficiency of polymeric materials, including the pervasive one, is a consequence of the development of initial microdefects which appear in polymers both due to external factors and during their processing. In the article, the problem of the detection of structural microdeficiency of various polymeric materials through an assessment of their structural parameters is solved. The considered materials possess approximately identical degree of crystallinity (60 – 66%), but different density. The express assessment technique of polymeric materials microdeficiency by the sorption method with the use of the academician M. M. Dubinin’s theory of volumetric micropore filling is developed and evaluated. On the basis of a quantitative assessment of sorption processes in polymeric materials, including elastomeric compositions – rubbers and rubberized fabrics, the existence of the initial local microdefects arising in the course of synthesis is established. In real polymeric materials, including elastomeric compositions – rubbers and rubberized fabrics, the existence of the initial local microdefects arising in the course of synthesis is established (the number of microdefects n varies from 1x1017 sm-3 to 6x1019 sm-3 , and the rated linear size k – from 2 nm to 7 nm). The general reduction of microdeficiency in rubberized fabrics in comparison with initial rubber is revealed and rationalized
483 kb

STUDY OF THE INTERACTION OF POLYSTYRENE-AZO-O-PHENOL-AZO-RHODANINE WITH ZINC IONS AND CADMIUM

abstract 1181604067 issue 118 pp. 1086 – 1096 29.04.2016 ru 676
Since the industrial revolution a huge amount of pollutants emitted annually into the water most of which is occupied by toxic metals. These metals widely distributed in the environment and of accumulation of a threat to human health. It is known, that cadmium and zinc at high concentrations have a negative impact on nature. In modern wastewater treatment technology we widely use polymeric sorbents with chelating properties. The use of polymeric chelating sorbents (PCS) usage allows separating individual or group trace elements from large volumes of solutions of complex composition, lowering the limit of detection, eliminating or reducing significantly the impact of macrocomponents which increases the cleaning efficiency. The article presents the results of a study of conditions of interaction of zinc (II) ions and cadmium (II) with PCT - polystyrene-azo-o-phenol-azo-rhodanine. We found the optimal values of the conditions for zinc (II) ions and cadmium (II) sorption. We investigated the effect of interfering of the macro- and micro- water components with the sorption of the ions studied. Maximum desorption of metal ions is achieved by washing the concentrate with 10 ml of 2M hydrochloric acid. The data indicate availability of the investigated sorbent for concentration and separation of zinc (II) ions and cadmium (II)
131 kb

QUANTITATIVE AND QUALITATIVE DETERMINATION OF ENZYMESANTIOXIDANTS CONTAINED IN HORSERADISH GROWN IN THE ASTRAKHAN REGION IN THE SUMMER AND AUTUMN

abstract 1181604089 issue 118 pp. 1377 – 1386 29.04.2016 ru 720
The article is devoted to the study of enzymesantioxidants contained in horseradish root. The article provides a detailed analysis of the sources of information, aimed at clarifying the content of enzymesantioxidants contained in horseradish root, grown in the Astrakhan region in the autumn and summer. During the analysis of the literature, it was found that the content of enzyme-antioxidants in the root of the horseradish is not constant and depends on climatic conditions, planting time and harvest time. The content of antioxidants in the root of horseradish grown in the Astrakhan region in the summer-autumn period was studied using by the method of A.N. Bach and A.I. Oparin. 2 g of horseradish roots contains the number of enzymes - antioxidants able to expand for 30 min (1,547 • 100) / (20 • 1) = 77.35 mg of hydrogen peroxide in 1 min - 2.56 mg. 1mkmol As hydrogen peroxide is 0.034 mg, in 2 g horseradish contains 76 E enzyme - antioxidants (or E 38 1 g horseradish). The results of this work will form the basis for the creation and study of new enterosorbent with antioxidant functions. Enterosorbent prepared by adsorption on starch antioxidants such as peroxidase, catalase, and ascorbic acid, from aqueous extracts of plant material
190 kb

TO THE STUDY OF ADSORPTION OF ENZYME-ANTIOXIDANTS ON STARCHES DERIVED FROM HORSERADISH TO CREATE ENTEROSORBENT WITH ANTIOXIDANT PROPERTIES

abstract 1181604095 issue 118 pp. 1459 – 1468 29.04.2016 ru 525
The article is devoted to studying adsorption of enzymes, antioxidants contained in horseradish root on starch to create enterosorbent with anti-oxidant properties. For this goal, we have studied adsorption isotherm calculated constants, thermodynamic parameters (change of enthalpy, entropy, and isobaric-isothermal potential); sorption kinetics of enzyme-antioxidants on starch and calculate the main characteristics. The method of producing of enterosorbent - antioxidant on based starches has been developed based on the experimental data. The ready sorbent is a white powder having no taste and smell. Insoluble in biological fluids and water. It is the solid component. The enterosorbent can be used to protect the gastrointestinal tract of humans and animals against a wide variety of oxidants and peroxide. The results of this work will form the basis for the study of the antioxidant properties of the resulting enterosorbent
139 kb

INVESTIGATION OF ASCORBIC ACID ADSORPTION ON KSMG SILICA GEL

abstract 1191605091 issue 119 pp. 1356 – 1365 31.05.2016 ru 764
The article studies adsorption of ascorbic acid on KSMG silicagel. The experimental results, the basic thermodynamic characteristics of ascorbic acid adsorption on oxide silicon have been used for treatment of adsorption mechanism of ascorbic acid on silica KSMG. Results of the study ascorbic acid adsorption on silica gel KSMG may be used for further identification of it in the various objects
140 kb

SYNTHESIS OF SUBSTITUTED ISOXAZOLO[5,4-b]PYRIDINE AND THEIR ANTIDOTE ACTIVITY

abstract 1221608034 issue 122 pp. 471 – 480 31.10.2016 ru 547
To develop the novel herbicide antidotes for the sunflower vegetative plants, the group of chemical compounds, belonging to the derivatives of isoxalopyrazolopyridines was synthesized and their antidote activity both in the laboratory and field experiments was studied. The compounds with a high antidote effect were found
258 kb

PERSPECTIVE MODIFIERS FOR ANIONEXCHANGE MEMBRANES BASED ON POLYMERS WITH QUATERNARY NITROGEN ATOMS, WHICH INCLUDED IN FIVE- AND SIX-MEMBERED HETEROCYCLIC RINGS

abstract 1231609085 issue 123 pp. 1256 – 1267 30.11.2016 ru 563
The present work describes the chemical synthesis of poly-N,N-diallyl pyrrolidinium bromide and polyN,N-diallyl morpholinium bromide - high-molecular compounds containing quaternary nitrogen atoms, which included in two five- and/or six-membered heterocyclic rings. These polymers are perspective modifiers for industrially produced anion-exchange membranes, the use of which should significantly improve the resistance to degradation of the membranes at over-limiting current regimes. The structure of obtained polymers was characterized by FTIR, 1H and 13C NMR spectroscopy. The optimal reaction conditions, which increase the yield of desired products, were defined. It is shown that is preferable to use 1-butanol as a solvent and benzoyl peroxide as an initiator
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