V. V. Barelko

Use of solutions of radiation-synthesized telomers of tetrafluoroethylene to modify glass fiber

In this work, we have suggested a new approach to fabricating fluorine-containing glass fibers based on the infiltration of glass-fiber filler by radiation-synthesized telomer solutions of tetrafluoroethylene. The radiation-chemical synthesis of tetrafluoroethylene telomers has been carried out in some solvents, their thermal stability has been studied, and the effectiveness of various telomers has been evaluated.

Development and investigation of new-generation catalysts on a woven fiberglass support for styrene refining from the phenylacetylene impurity by selective hydrogenation

148 The main purpose of this work was to study the effi ciency of our developed new generation catalysts on a woven fiberglass support for removing the phenylacet ylene impurity from the styrene fraction by selective hydrogenation in the process of styrene production from ethylbenzene. Phenylacetylene forming at the ethylbenzene dehydrogenation stage is quite an unde sirable impurity in the styrene fraction because it leads to uncontrollable polymer chain growth in polystyrene production and significantly impairs the quality of this large scale product.

Preparation and properties of composites based on caramelized aluminoborosilicate fabric and tetrafluoroethylene telomers

New composites based on activated caramelized aluminoborosilicate glass fabric and radiationsynthesized tetrafluoroethylene telomer solutions were prepared, and their properties were studied. The properties of materials prepared from standard commercial and caramelized glass fabrics were compared.

Liquid-Phase Hydrogenation of Aromatic Mononitro Compounds on Supported Porous Catalysts at Partial Hydrogen Pressures Lower than 0.1 MPa

The influence of the hydrogen partial pressure varied in the interval (4.3–100) × 103 Pa on the kinetics of liquid-phase catalytic hydrogenation of aromatic mononitro compounds in the presence of platinum and iridium supported on activated carbon in various percent ratios (Pt/C-2.5% and Ir/C-5%) was studied for 3,4-dichloronitrobenzene as example. A decrease in the hydrogen partial pressure leads to a significant decrease in the rate of the nitro compound consumption and in the yield of the intermediate arylhydroxylamine. A kinetic mechanism of hydrogenation of the nitro compound, satisfactorily describing the experimental data, was suggested.

Study of pyridine-modified platinum- and palladium-containing selective-hydrogenation catalysts on fiber-glass woven support

Experimental results on the influence exerted by pyridine additives on the selectivity of the process in which the styrene fraction is purified to remove the microscopic admixture of phenylacetylene at low (up to 30°C) temperatures by selective hydrogenation with catalysts on an aluminoborosilicate or silica matrix with filler-metals in the form of platinum or palladium are presented. It was shown that pyridine-modified catalysts in these systems are effective in the selective hydrogenation of phenylacetylene for purification of raw styrene. The modification of a platinum catalyst on the aluminoborosilicate support results in that a deep degree of purification (>95%) is achieved even at low (up to 50°C) temperatures. Use of catalysts composed of 0.160 wt % Pt and silica woven-glass fabric, modified with pyridine additives, leads to a substantially lower loss of styrene (from 0.48 to 0.31% in some cases) in the temperature range of 30–50°C. It was demonstrated that addition of substances containing a unshared electron pair can noticeably affect the selectivity of the process in which the styrene fraction is purified from its impurity content even in the order of 0.01%. Depending from the substrate composition and active filler-metal, the temperature, together with changing the support properties, exerts varied influence on modified metallic catalysts, which is manifested in change in the activation energy and, as a consequence, in that of the hydrogenation mechanism.

Catalytic transformations of fluids

Fluids play a very important role in processes of the chemical and physical evolution of crustal and mantle rocks. The influence of certain rocks on chemical reactions between fluid components is studied. Experimental results of the catalytic activity of serpentinite, ophitic gabbro, and lizardite–antigorite asbestos relative to vapor conversion of methane (CH4) have been obtained with the formation of syngas at atmospheric pressure and temperatures up to 850°C. Such transformations are assumed to be able to take place under natural conditions in fluid systems that accompany massifs of seabed ultrabasic rocks, as well as kimberlite pipes. Proceeding from the studies performed, options of the practical use of various crustal rocks as catalysts of fluid transformations have been proposed. The experimental results confirm the initial theses of the authors’ concept with respect to the role of heterogeneous–catalytic mechanisms of transformations of fluids in the Earth’s crust.