Abstracts

№2, 2016

Effect of Chlorination Conditions at the Synthesis of the Neodimium bis-(2-ethylhexyl)phosphate-Based Catalyst on Its Activity and Properties of cis-1,4-Polyisoprene

Novikova E.S., Bodrova V.S., Vasil’ev V.A., Drozdov B.T.

The influence of both the nature of chlorinating agent and chlorination conditions in the synthesis of neodymium bis-(2-ethylhexyl)phosphate on its catalyst activity and properties of cis-1.4-polyisoprene obtained has been studied. The catalyst is found to be the most active if a chlorine-containing compound is fed the last in the synthetic process. Diisobutyl-aluminum chloride (DIBAC), ethyl-aluminum sesquichloride (EASC), aluminum-chloride/diphenyl-oxide comlex (AlCl3∙2DPO) and CCl4 were examined as chlorinating agents. When using DIBAC, EASC and AlCl3∙2DPO, homogenous catalysts arise with a high activity in isoprene polymerization, unlike a system containing CCl4. However, the use of CCl4 together with organoaluminum compound (triisobutylaluminumm, TIBA), results in the formation of a catalyst of high activity in isoprene polymerization. It opens the possibility to simplify and make cheaper the process of catalyst synthesis.

Key words: neodymium bis(2-ethylhexyl)phosphate, chlorinating agent, CCl4, polymerization, polyisoprene, microstructure, IR-spectroscopy, gel permeation chromatography

Influence of the New Type SSR’s Antiaglomerators “Quntislip” Series on the Properties of cis-1,4-Polyisoprene

Nasyrov I.Sh., Faizova V.Yu., Zhavoronkov D.A., Kavun S.M., Kolokolnikov A.S., Medzhibovsky A.S.

The results of the industrial tests of cis-1,4 isoprene containing a series of a new crumb antiaglomerators (AA) under the trade name "Quantislip " are presented. AA introduced in rubber at a degassing stage. Tests were run at the JSC "Sintez-Kauchuk". New AA of Quantislip series, developed by the LLC «NPP QUALITET», provide decrease of calcium and chlorine ions concentrations in sewage and their alkalinity. Improvement of mechanical, strength in particular, properties of technical carbon filled rubber based on cis-1,4 polyisoprene (SKI-3 trade mark), containing AA is shown. The AA under the name Quantislip BM-2R (trade mark) of optimal structure is developed specially for rubber SKI-3 manufacture. At the use of BM-2R the stearic acid, formed in industrial SKI-3 with suspension of calcium stearate as AA, is excluded from rubber. Mechanism of appreciable growth of the stress-strain properties of vulcanizates filled with carbon black, based on SKI-3 containing BM-2R, is under discussion. The possible cause of this effect is the increase of rubber/filler interaction as a result of excluding of the competition between the adsorption of polymer chain segments and stearic acid for the active centers on the surface of carbon black.

Key words: cis-1,4-Polyisoprene, s-synthetic rubbers separation agents, antiaglomerators, SSR production, SSR separation, adhesion reducing agent, stress-strain properties, carbon black/polymer interaction

Effect of the Nature of Oil-Extender on the Properties of Rubber SKS 1739

Nasyrov I.Sh., Kapanova R.A., Faizova V.Yu., Sheludchenko V.A., Ratbil A.B., Maslov A.N., Markin A.V., Sologubov S.S., Shalashova A.A., Schepalov A.A.

A comparative lab analysis of two different samples of oil-extended rubber SBR1739, containing TDAE and PN-6k oils respectively was performed. For the purpose of the test, the non-carcinogenic TDAE oils were used: Norman 346, Norman 223 and Norman 239, produced by Orgkhim. The tests revealed a distinct connection between the hydrocarbon content of the extender oil and the properties of the resultant rubber. Viscosity, deformation, strength and vulcanization properties of raw and vulcanized rubber were measured by standard methods. Glass transition temperature Tg of both oils and rubbers were measured by DSC (DSC 204 F1 Netzsch-Gerätebau, Germany). The higher is Tg of oil the higher is Tg of rubber at the same oil content. The higher content of all types of Norman oils provided proportional decrease of rubber Tg Oil Norman 223 and this oil containing rubber are of the lowest Tg. Oil Norman 346 delivered the best extender performance, however oil Norman 223 provided the possibility to lower Tg of rubber SBR1739 on average in 4º. Controlled adjustment of the oil’s chemical composition helped produce rubber and vulcanized compounds based on this rubber with customized physical and chemical properties. Thanks to the proper selection of the low-PCA extender oil the project eventually reached its goal of producing an industrial trial lot of SBR1739 rubber with customer specific customized properties.

Key words: oil-extender, TDAE oils, Orgkhim, rubber SBR1739, glass transition temperature of oil, glass transition temperature of rubber,

DSC 204 F1, viscosity, mechanical properties, vulcanization properties

Study of Elastomer Composition Reinforced by Modified Carbon Fibres

Maskalyunaite O.E., Nekrasova V.V.. Zabolotskikh S.Yu., Grakovich P.N., Ivanov L.F., Shelestova V.A.

The possibility of chemically modified carbon fibres "Belum" (Hydroxycellulose fibres) to improve the wear resistant of elastomer compositions was studied. Shredded fibers of the length of the main fraction of 50–100 microns were in use. Сhemical modification of «Belum» was carried out in plasma of electric discharge in a medium of fluoroorganic compounds. As a result the coating of fluoroelastomer of few tens of nanometers thick is formed. In chemical composition it is similar to PETF. Microstructure of modified carbon fibers was studied by means of electron microscopy. The improvement of wear resistance of experimental elastomer composition based on SKF-26 was shown. The improvement of the aging resistance measured by the change of compression set at deformation 20 % under accelerated heat aging at temperatures 100, 125, 150, and 200 °C was also shown. The comparative stand tests of different types of moving seals, prepared with the use of carbon fibers «Belum», showed significant advantage. Service tests of technical goods of experimental elastomer composition also showed the good results. Mechanism of the effects of plasma modification of fibers is under consideration.

Кey words: carbon fibers «Belum», electron microscopy, plasma modification, fluoroelastomer composition, wear resistance, heat resistance, stand tests of moving seals, service tests of rubber goods

Effect of Acid-Base Balance of the Surface of Silica Particles on the Structure and Properties of Compositions based on Butadiene Acrylonitrile Rubber

Ovsyannikova D.V., O.Yu. Solovyeva O.Yu., E.A. Indeikin E.A.

The acid-base balance of particle surface of the different types of silica filler (SF) is determined. Its influence on the structure and properties of composites based on NBR is studied. Close to linear correlation between the ability of silica particles to flocculate and the concentration of acid centers (AC) on its surface is obtained. The absence of well-defined effect of dispersion of filler particles is found. Of all studied assortment, SF of the higher concentration of AC shows the higher ability to form flocculation structures at the equal rate of silica. Increase of AC results in the growth of the relative content of physical and covalent bonds in binary mixtures NBR/SF. To decrease the negative effects connected with the formation of flocculation structures, including initial curing period, the selection of SF of reduced concentration of AC is recommended.

Key words: silica filler, coagulation-flocculation structures, acid-base properties, NBR, RPA-2000, MDR-2000, Payn effect

New High Structure Carbon Black of Series OMCARB for Reducing Rubber Hysteresis.

Part I. Peculiarities of Carbon Black Structure and Properties

Moiseevskaya G.V., Razdyakonova G.I., Petin A.A., Strizhak E.A.

The aim of the work was to study the complex of the properties of carbon black СН85 of series OMCARB and compare it with properties of standard carbon blacks N339 and N234. Morphological characteristics, globule and aggregates size distribution, surface area, micropore area fraction, primary aggregates branching, as well as mechanical and chemical properties were measured and calculated. The mean aggregates size of СН85 is higher, than that of N339 and N234, aggregates have the more open and branch structure. Iodine adsorption of СН85 is nearly the same, as that of N339 and lover than that of N234. Index of low hysteresis behavior, calculated on the basis of structure data is much better for СН85. It opens the possibilities to use this type of carbon black to develop elastomer materials of low hysteresis.

Keywords: carbon black, morphology, heterogeneity, aggregates branching, surface area, iodine adsorption, hysteresis, index of low hysteresis behavior

Evaluation of the Plasticizing Action of Dispersants of Rubber Compounds Based on Butadiene Acrylonitrile Rubbers

Dolinskaya R.M., Prokopchuk N.R., Korovina Yu.V.

The influence of dispersants on the properties of rubber compounds based on butadiene-acrylonitrile rubbers BNKS-18AMN and BNKS-28AMN (of 18 and 28 acrylonitrile content correspondently). Compounds are dedicated to production of articles by injection molding. Four types of dispersants were tested. The best effect was shown for two dispersants: INT 159 and NMPA. The use of the both of them results in sufficient decrease of viscosity and improvement processing as well as mechanical properties. Effect of the content of these dispersants was also studied. Comparison of the complexes of properties of row and vulcanized rubbers shows the slightly best results, including heat resistance of seals, for INT 159. However NMPA is of the Belarus production. So NMPA is recommended as dispersant for injection molding compounds. The optimum content of NMPA is found to be 2.00 mph, providing the best complexes of service properties.

Key words: BNR rubber compounds, dispersants, rheological properties, physical and mechanical properties, functional group, low molecular weight polymer.

Modification of Rubber-Epoxide Matrix by Carbon Containing Fillers for Heat-Shielding Materials

Istomina T.S., Tiunova T.G., Jakushev R.M., Moskalev I.V.

The materials based on rubber-epoxide matrix, filled with coal-tar pitches and oil coking additive have been studied. The influence of the fillers on degradation rate of the cured material and coke residue has been studied using thermogravimetric, differential thermal analysis and differential scanning calorimetry. Thermal oxidative stability was found to be reduced after introduction of coal-tar pitches to the polymer matrix, and increased after introduction of oil coking additive. At isothermal and dynamic regimes the most amount of coke residue is formed at annealing of the composition containing oil coking additive. Coke residue of this material is burnt up within the widest temperature range. The influence of the filler nature and experimental temperature on mechanical characteristics of the material has been investigated. It was found that at elevated temperatures the best deformation and strength properties are achieved in the case of oil coking additive. The possibility of material application as a heat shielding coating has been estimated.

Key words: heat-shielding materials, olygomer matrix, epoxy resin, coal-tar pitch, coking additive, thermal oxidative degradation, TGA, DTA, DSC, mechanical properties

Polyurethane Elastomers on the Base of Oligobuthanduole Krasol LBH-3000 and Oligodienediisotsianate

Medvedev V.P., Vaniev M.A., Sakibaeva S.A., Beloborodova A.E.

Effect of content of functional groups and amount of components on the process of formation of three-dimensional structure of polydienurethanes was studied. Krasol LBH-3000 oligobutadiendiole based compositions, chain branching agents (CBA) aromatic diamines 3,5-dimethylthiotoluilendiamine (Etakyur 300), 3,3-dichloro-4,4-diaminodiphenylmethane (Diamet X) and glycerol were components of the processes. The effect of the ratio between the functional groups of the isocyanate hardener, and oligomeric diamine rubber, the amount and type of CBA on the mechanical, in particular strength, properties of compositions was determined. Almost linear increase of tensile strength with the ratio of isocyanate, hydroxyl- and amine groups was fixed. It was found that the highest mechanical properties of elastomers are reached for composition curing by isocyanate prepolymer NN22 in the presence of Etakyur. The maximum level of strength is achieved at the excess of isocyanate component. It is connected with the possible interactions of prepolymer both with hydroxyl groups of oligodiol and amino groups of Etakyur and formation of rigid urea-urethane and biuret structures of high energy of intermolecular interaction. Compatibility of oligomer and isocyanate components provides the improvement of the strength properties of elastomers.

Keywords: oligobutadiendiole Krasol LBH-3000, polydienurethany, oligodiendiizotsianat, the ratio of functional groups, strength properties

Optimum Conditions of Isoprene Bulk Polymerization

Elfimov V.V.

The work continues a series of studies on isoprene liquid-phase polymerization in bulk run in low-volume cells. Studies based on the use of developed mathematical model. In this paper also both by calculations and experimentally the optimum process has been shown to occur in low-volume cylinders, of maximum 3–4mm-high reaction layer. Time dependencies of temperatures, mean monomer conversion, polymerization time were calculated and compared with that obtained for the half-spherical one (low-volume cell). Polymerization temperature and time in different layers of cylinders was also calculated. The data obtained evidence that the cylindrical reactor is more productive in any case, as compared to the low-volume half-spherical one, even in the polymerization at a lower temperature. Polyisoprene obtained is not only as good as commercial SKI-3 samples but sometimes are superior in physical and mechanical characteristics, microstructure and gel content. Design of polymerization equipment is recommended.

Key words: isoprene rubber, polymerization in bulk, mathematical model, low-volume polymerization cell

Innovative Technologies of Production of Reinforced Elastomer Composites

Grishin B.S.

Review devoted to analysis of theory and practice of elastomer reinforcement, classification of reinforcing fillers, the structure of filled elastomer composites and iinnovative processing methods of their production.

Key words: elastomer reinforcement, , two-zone structure, network structure, base and addition reinforcing fillers, reinforcement modifiers, interphase bonds, liquid phase («wet mix») and integral processing