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The effect of nanocarbons of different origin - C60 fullerenes, single-wall carbon nanotubes (SWCNTs), and, as a model, carbonised starch (PSC) - on the structure and properties of a filled and an unfilled polyurethane matrix was investigated. The nanocarbons were introduced into part of a polyurethane prepolymer and treated in an ultrasonic field. The specific surface of the fillers was determined by the method of thermal desorption of nitrogen on a Quantachrome NovaWin instrument (Quantachrome Instruments, USA). Small-angle X-ray scattering (SAXS) data obtained on an Anton Paar (Austria) diffractometer suggest a high surface roughness of the SWCNT particles (fractal dimension D = 2.9) and a low surface roughness of the C60 and PSC (D = 2.0), as well as constancy of the structural organisation of the domains of rigid blocks at distances of the order of 3 nm or less. Large-angle scattering (Bruker D2 Phaser) makes it possible to draw a conclusion concerning the preferential distribution of particles of highly dispersed nanocarbons among elements of the free fluctuation volume of the polyurethane matrix. As a consequence, these particles have no effect on the morphology of elements of the matrix. The lack of dependence of the glass transition temperature, determined by differential scanning calorimetry (DSC 8000, PerkinElmer), on the presence and nature of nanocarbons indicates the constancy of motion of the polymer macromolecules. Data of all these methods indicate that nanocarbon particles are distributed in the interdomain space and preferentially among areas of local stress of the polyurethane polymer matrix. This conclusion is in good agreement with the strength parameters obtained (Tinius Olsen H10KT tensile testing machine, UK): a 20-50% increase in the stress under 100 and 200% elongation and an increase of up to 80% in the tear strength. [ABSTRACT FROM AUTHOR]

The importance of developing GOST standard specifications for the quality control of different grades of synthetic rubber produced in Russia, incorporating standard elastic strength and rheometric characteristics, is shown. Here, ISO and ASTM test procedures must be used, as well as positive features of Russian technical documentation. The need for and the possibility of producing and certifying home-produced reference ingredients and carbon black are also shown. The creation of a unified base of reference materials (ingredients, carbon black, etc.) will make it possible to increase the reliability of product quality control at synthetic rubber, tyre, and mechanical rubber goods plants. [ABSTRACT FROM AUTHOR]

Now there is not a single area of industry that can do without adhesive elastomer materials. Composites based on synthetic rubbers comprise 75% of the total volume of adhesive materials produced, which is due to the combination of unique properties typical of the elastomer base of the adhesive. The base of many imported adhesives for the bonding of rubber to metal is chlorinated natural rubber. As an alternative, chlorinated synthetic isoprene rubber has been proposed, developed at the Scientific Research Institute for Synthetic Rubber in St Petersburg. The chlorinated isoprene rubber was compared with imported chlorinated natural rubber in adhesive composites, and the physicomechanical properties of mixes based on a blend of chlorinated rubber and nitrile butadiene rubber were investigated. The investigation was conducted on chlorinated natural rubber of grade Pergut S20, chlorinated isoprene rubber SKI-3, and nitrile butadiene rubbers of grades BNKS-28AMN and SKN-26S. The influence of the ratio of chlorinated rubber to nitrile butadiene rubber and the technological factors of mix preparation on the properties of films produced from them was established. It was shown that, in terms of the level of properties, home-produced chlorinated rubber can be used as the base for adhesives for hot bonding of rubber to metal instead of imported Pergut S20. [ABSTRACT FROM AUTHOR]

The results of modifying polystyrene with thermooxidised starch with different molecular weight characteristics are presented. An assessment is made of the influence of the additives used in different concentrations on the characteristics of the initial polymer. [ABSTRACT FROM AUTHOR]

The article discusses the use of a TiCl4-Al(i-C4H9)3electron donor-toluene low temperature catalytic system in determining the basic principles of the industrial production of highly homogeneous cis-1,4-polyisoprene. The authors tackle the need to achieve an improvement in quality and in homogeneity of the SKI-3 rubber. Also explored is the polymerisation of isoprene on the basis of the principle.

The results of investigating the effect of potassium salt of 1,2-cyclohexanedicarboxylic acid on the thermophysical and physicomechanical properties of homopolypropylene are presented. It is shown that the use of the given nucleator at the extrusion stage makes it possible to produce polypropylene with high elastic strength characteristics. Improvement in the physicomechanical properties of the polymer modified with potassium salt of 1,2-cyclohexanedicarboxylic acid is accompanied with an increase in the degree of crystallinity of the polypropylene. [ABSTRACT FROM AUTHOR]

The results of investigating the effect of 3,6,9-triethyl- 3,6,9-trimethyl-1,4,7-triperoxonane on the melt flow and organoleptic properties of polypropylene are presented. It is shown that the application of the given peroxide at the extrusion stage makes it possible to synthesise a polymer with controllable impact strength and a reduced content of volatile substances by comparison with other types of peroxide. [ABSTRACT FROM AUTHOR]

The article presents an investigation into the thermo-oxidative degradation of ethylene-propylene-diene (SKEPT) copolymers, as well as their qualitative and quantitative composition of their volatile breakdown products, using Russian and foreign ethylene-propylene-diene elastomers. Gas chromatography was applied to determine the qualitative composition of the gaseous degradation products.

The article presents an investigation of the microstructure and its influence on the thermo-oxidative properties of ethylene-propylene-diene copolymers (SKEPT) rubbers using Russian and foreign ethylene-propylene-diene elastomers with different Mooney viscosities and different comonomer contents. Infrared spectroscopy was used in analyzing the microstructure of the polymer chains. It has confirmed the dependence of SKEPT service characteristics on microstructure.

This article presents a study which investigated a method of breaking down crosslinked polymer accretions using a stable nitroxyl radical for the cleaning of production equipment, particularly polybutadiene synthesis reactors. The study was conducted on a laboratory unit modelling a butadiene polymerisation reactor. Findings revealed the optimum temperature, time and concentration parameters for the effective cleaning of the butadiene synthesis reactor.

At the Nizhnekamskneftekhim Open Joint Stock Company, technology has been developed and introduced into operation for the production of new SKD-L butadiene rubber suitable for the modification of thermoplastic materials. It has been shown that the use of SKD-L polybutadiene in the production of high-impact polystyrene (HIPS) makes it possible to produce a polymer with the desired combination of properties, and also to lower the manufacturing cost of high-impact plastics produced in Russia, and to ensure independence from the foreign market. [ABSTRACT FROM AUTHOR]