Voprosy khimii i khimicheskoi tekhnologii (Issues of Chemistry and Chemical Technology)

4-6

Authors: O.A. Pivovarov

On the occasion of 85th anniversary, the history, current state and prospects for further development of the Ukrainian State University of Chemical Technology are reviewed. The role of prominent chemists in the foundation and establishment of the University and its prestige in Ukraine and abroad is shown.

25-45

Authors: F.I. Danilov, V.S. Protsenko, Yu.E. Sknar

The investigations devoted to the electrochemical synthesis of composite coatings are systematically reviewed. The co-deposition of nonmetallic phase is shown to proceed via two main mechanisms. The first mechanism presupposes that the particles of nonmetallic phase are initially added to the suspension electrolyte and then incorporated into the deposit. According to the second mechanism of the synthesis of composite electrochemical coatings, the dispersed phase is formed in the near-electrode layer as a result of electrochemical or chemical transformations with the participation of electrolyte constituents, the particles of the dispersed phase being not initially introduced into the bulk solution but generated in situ directly in the near-electrode zone or on the electrode surface. The electrodeposition of composites from suspension electrolytes is illustrated by the electrochemical syntheses of Fe/ZrO2, Fe/TiO2 and Ni/ZrO2 coatings. The kinetics of co-deposition proved to obey the theory developed by Guglielmi. Methanesulfonate electrolytes can be used for composites electrodeposition. The methanesulfonate electrochemical systems are distinguished by their high productivity, enhanced content of nonmetallic phase in coatings, and valuable physicochemical properties of deposits obtained. The fabrication of composites by the direct formation of a dispersed phase in the near-electrode layer in the course of electrolysis is illustrated by the deposition of Ni/CeO2 composite from the methanesulfonate electrolyte and Cr/C composite (i.e. containing chromium carbides) from the sulfate electrolyte on the basis of Cr(III) salts. The microstructure and some physicochemical and service properties of the obtained nanostructured composite coatings are characterized.

53-64

Authors: V.I. Markov, O.K. Farat, S.A. Varenichenko, E.V. Zaliznya, Yu.P. Stroev

This review contains data on the reactivity of heminal azine − 5',6',7',8'-tetrahydro-1'H spiro[cyclohexane-1,2'-quinazolin]-4'(3'H)-one and the chemical properties of his rearrangements products. The main results of the investigations are presented which have been performed at the TOSPhP department of Ukrainian State University of Chemical Technology during last five years. We have studied in detail the Mannich aminoalkylation of this compound with primary amines which leads to the formation of a heterocyclic system containing an annelated azabicyclic fragments. The hydrolysis of the indicated spirans gives 3-azabicyclo[3.3.1]nonanes. These compounds show a variety of biological activity (for instance, analgetic and antimicrobial one). Hence, the development of new methods for preparing novel polycyclic 3-azabicyclo[3.3.1]nonanes is an actual goal. We investigated the formylation of 5',6',7',8'-tetrahydro-1'H-spiro[cyclohexane-1,2'-quinazolin]-4'(3'H)-one and discovered a new multistage domino reaction which enables to obtain tricyclic acridine systems due to the deep rearrangement of the carbon skeleton. In the present work we showed that the rearrangement of 5',6',7',8'-tetrahydro-1'H-spiro[cyclohexane-1,2'-quinazolin]-4'(3'H)-one and its analogues under Vilsmeier-Haack conditions is of a general nature. The reaction is sensitive to increased temperatures and in the case of some derivatives it is nonselective and gives a hardly separable mixture of resinous products. It is proposed to consider the rearrangements of azine, which are based on pyrimidine-to-pyridine transformation induced electrophile attack, as an AERORC-process.

69-73

Authors: O.S. Panteleieva, V.I. Tkach

The present paper is devoted to the interaction between organic cation of Pachycarpinum and heteropolyanions (HPA) of Keggin structure of 12-molybdophosphatic heteropoly acid РМо12О403–. The marginally soluble associates obtained have been used as electrode-active substances for the synthesis of the plasticized membranes of ion-selective electrodes which are reversible with respect to the organic cation of Pachycarpinum. We developed a new technique for the determination of the content of pahicarpine hydroiodide in a substance and aqueous extracts of lupine seeds and roots; the technique is based on the potentiometric method with the use of an ion-selective electrode which is sensitive to the organic cation of pahicarpine hydroiodide. The HPA of Keggin structure РМо12О403– was chosen as an analytical reagent. This analytical reagent is used due to its ion-exchange properties and ability to easily rebuild; it can deposit large organic cations to form poorly soluble compounds of constant composition which are soluble in organic solvents and insoluble in water. In the course of the interaction between HPA and organic cation of pahicarpine hydroiodide, a reaction occurs with the formation of a marginally soluble compound with an ion-associative bond nature. The synthesized compound is used as an electroactive substance for the ion-selective electrode which is reversible with respect to the organic cation of pahicarpine hydroiodide. Thus, according to the data obtained, an associate of the general formula (Pah)3PMo12O40 was used as an electroactive substance for the developed ion-selective electrode. The developed ion-selective electrode with a plasticized polyvinylchloride membrane is sensitive to the organic cation of pahicarpine (Pah1+). The proposed analytical techniques of a direct potentiometric determination of Pachycarpinum in a substance and aqueous extracts of lupine seeds and roots are characterized by sensitivity, rapidity and accuracy.

78-85

Authors: V.D. Barsky, G.A. Vlasov, А.А. Pivovarov, A.V. Kravchenko

In any spatial zone the main factor, which forms variety of chemical composition, structure and properties of coal, is the time from the beginning of "geological history" of maternal plant residues. Furthermore, on any segment of the "geological age" even in relatively close spatial zones the coals of various "chemical age" can be formed because of varying intensity of natural impacts and, first of all, temperature and pressure. Since the latter ones "after all this time" are not actually identifiable, quantitative description of metamorphism was carried out by establishing time-dependent patterns of elemental composition changing at the background of its "random", but causative fluctuations. The report deals with patterns of changing in the course of metamorphism of the elemental composition of solid fuel and mathematical model built for description of the said patterns as a function of carbon content. With the use of experimental data of artificial carbonization it is shown that it represents an experimental model of natural metamorphism. The elemental composition of solid fuel "molecule" has been formulated. Investigation of the dynamics of carbonization changes allowed defining specific points on the axis of metamorphism, and drawing up the material balance of this process showing that coking coals are concentrated on the axis of metamorphism in the narrow region near the point where 16 hydrogen atoms fall on each oxygen atom in solid fuel "molecule".

92-103

Authors: A.I. Nesterenko, Y.S. Berlizov

The use of cavitation leads to an increase in the yield of light oil by the thermal cracking of oil stock. It has been experimentally established that the yield of diesel fractions depends on the composition and properties of oil stock as well as the cavitation parameters, such as temperature, pressure, viscosity, volume flow rate, number of cavitation cycles, geometry of the centrifugal vortex chamber etc. In addition, the process occurs at a high temperature and pressure and oil stocks are highly corrosive. Therefore, it is very difficult to ascertain the influence of cavitation by experimental studies. Thus, we performed the computer simulation of the process under consideration. It is shown that the axial, radial and peripheral velocities of raw materials in the centrifugal vortex chamber pronouncedly differ in their magnitude. The full velocity is high and reaches 43 m/s on the vortex surface. It is concluded that the cavitation region must be on the very vortex surface where the intensification of the hydrocarbons cracking takes place. The parameters of the cavitation region are determined from static pressures of a liquid in all points of the cavitation apparatus. The distribution of the static pressure of the liquid in the centrifugal vortex chamber is complicated, namely the cavitation region is a hollow truncated cone, inside which a cylindrical steam vortex is. The formation of a turbulent layer expands the cavitation region; the shape and size of the cavitation region being calculated based on the parameters of a real centrifugal vortex chamber.

119-124

Authors: A.Yu. Poloz, Yu.R. Ebich

The dispersed structure of epoxy resin compositions based on ED-20 filled with silicon carbide with varying dispersion degree is analyzed. These epoxide compounds are characterized by enhanced hardness on the Moos scale to ensure the wear resistance of composite materials. The density packaging fillers, average distance between particles fillers, and "free and specific free volume fillers" are chosen as parameters of the composites dispersion structure. The influence of "free volume fillers" on the dispersion degree is shown. When manufacturing highly filled epoxide compositions, it is worthwhile to introduce firstly filler with small particles for which a change of this parameter has virtually no effect on the average distance between the particles of the filler. Then coarse fillers should be introduced for which the dependence involved is significant.