Heterogeneous structure of cis-isoprene rubber and oligodiene diisocyanate blends

The structural peculiarities of cis-1,4-isoprene rubber, oligodiene diisocyanate, and derivative of phenol–formaldehyde resin blends have been studied by WAXS and SAXS methods and electron microscopy. It has been demonstrated that the addition of modifiers and further thermal treatment under conventional curing conditions change considerably the microheterogeneous structure and morphology and contribute to the improvement of the short-range order in the rubber matrix.     

Manufacture of films displaying liquid-crystalline structure

Reported is an attempt to attain orientation of macromolecules during extrusion of films of cellulose derivatives that led to the liquid-crystalline state of a polymer and resulted in enhanced film strength.     

The nature of temper brittleness of high-chromium ferrite

The reasons for development of 475°C brittleness of high-chromium ferritic steels are considered from the standpoint of fracture mechanics. It is shown that the general rise in the curve of temperature-dependent local flow stress has the decisive influence on the position of the ductile-to-brittle transformation temperature and the increase in it as the result of a hold at temperatures of development of brittleness. The established effect is related to the change in the parameters determining dislocation mobility, that is, the activation energy of dislocation movement in high-chromium ferrite and the resistance to microplastic deformation, both caused by processes of separation into layers of high-chromium ferrite and decomposition of the interstitial solid solution.Translated from Problemy Prochnosti, No. 7, pp. 71–75, July, 1994.     

Possible high-temperature superconductivity in fluoride materials

The results are presented of a study of fluorine-containing materials, the chemical compositions of which were chosen from calculations of the valence electron concentration in a single bond. In the resistance-temperature curves of the specimens, a narrow minimum was observed at T 40°C.Translated from Izmeritel'naya Tekhnika, No. 6, pp. 43–45, June, 1993.     

Fabrication of Si–C–N compounds in silicon carbide by ion implantation

The chemical variation and depth profile of silicon carbide implanted with nitrogen and overgrown with epitaxial layer has been studied using X-ray photoelectron spectroscopy (XPS). The results of this study have been supplemented by transmission electron microscopy (TEM) imaging and electron energy loss-spectroscopy (EELS) in an attempt to correlate the chemical and structural information. Our results indicate that the nitrogen implantation into silicon carbide results in the formation of the Si–C–N layer. XPS revealed significant change in the bonding structure and chemical states in the implanted region. XPS results can be interpreted in terms of the silicon nitride and silicon carbonitride nanocrystals formation in the implanted region which is supported by the electron microscopy and spectroscopy results.     

Polymer organic-inorganic materials for membrane technology,their characteristics and properties

Organo-inorganic nanocomposite glassy films are obtained by the sol-gel method via hydrolytic polycondensation reactions of silicon and titanium alkoxides in solutions of polymers of different chemical compositions. The polymer structure and interaction with oxides in the films are investigated by FTIR spectroscopy, atomic force microscopy, using a particle size analyzer and a number of physicochemical methods. The presence of nanosized (from ∼20 to 370 nm) particles of the oxides in the structure of hybrid films is confirmed. It is shown that the best practically useful properties are exhibited by the composite films with strong organo-inorganic polymer-oxide networks. Such films may be used for creating membranes and sorbents for water purification from harmful organic and ionic admixtures.     

The toxicological problems of disaster medicine in the Navy Fleet]

From position of the uniform concept of the accident medicine the problems of toxicological supply of the ships of MNF are considered. Peculiarities of chemical accidents in the ship conditions are marked. The question about principles of harmful chemical substances regulating, forming air environment of ship living quarters is discussed. The prospects of practical use of antidotal means, intended for protection of personnel from toxic action of carbon dioxide and chemical combinations, causing development of toxic edema of lungs are given.