scholarly journals TECHNOLOGICAL ADDITIVES FOR OIL AND PETROL RESISTANCE RUBBERS BASED ON BUTADIENE-NITRILE CAOUTCHOUCS

Author(s):  
Evgeny N. Egorov ◽  
Nikolay I. Kol'tsov ◽  
Nikolay F. Ushmarin

The article investigated the influence of various technological additives (zincolet BB 222, lubstab-01 and MA-L22) on the technological properties of the rubber mixture, physical, mechanical and operational characteristics of rubber based on nitrile butadiene caoutchouc BNKS-40AMN. Basic rubber mixture studied included caoutchouc, BC-FF percadox, zinc monomethacrylate, maleide F, triallyl isocyanurate, acetonanil N, MGF-9 and THM-3 oligoester acrylates, carbon black P 514 and other ingredients. The rubber mixture was prepared on laboratory rolls LB 320 160/160 in two stages. At the first stage, BNKS-40AMN caoutchouc was mixed with ingredients and processing aids. As technological additives, zincolet BB 222, lubstab-01 and MA-L22 were used. In the second mixing step, BC-FF percadox and vulcanization coagents were introduced. For the obtained variants of the rubber mixture the vulcanization characteristics were studied on an MDR 3000 Basic rheometer at a temperature of 170 °C. The rubber mixture prepared was vulcanized in a P-V-100-3RT-2-PCD type vulcanizing press at 150 °C for 40 min. Determination of elastic-strength and operational properties of rubber were carried out according to the standards existing for the rubber industry. The oil resistance of the vulcanizates was evaluated by changing their elastic strength after exposure to standard liquid SZHR-1 at a temperature of 125 °C, as well as by changing the mass of the samples after exposure to a mixture of isooctane with toluene at room temperature. It was found that the introduction of technological additives in the rubber compound improves the distribution of carbon black P 514 and powdered ingredients (zinc monomethacrylate, maleide F, triallyl isocyanurate, acetonanil H) in the caoutchouc matrix. Increased elastic strength indicators and their smallest changes after exposure to aggressive hydrocarbon media is characterized a rubber containing technological additive MA-L22. A comparison of technological, elastic-strength properties and resistance to aggressive media for rubbers containing butadiene-nitrile caoutchoucs BNKS-18AMN, BNKS-28AMN and BNKS-40AMN with optimal technological additives for them was done. It has been established that rubber containing BNKS-40AMN and technological additive MA-L22 is characterized by improved vulcanization properties, increased elastic strength indicators and their smallest changes after exposure to aggressive hydrocarbon media.

Author(s):  
Ivan S. Spiridonov ◽  
Nikolay F. Ushmarin ◽  
Evgeniy N. Egorov ◽  
Sergey I. Sandalov ◽  
Nikolay I. Kol'tsov

Influence of various technological additives on processability of the rubber mixture and the elastic-strength properties of rubber based on butadiene-nitrile caoutchuc BNKS-28AMN was investigated. The study was conducted with the aim of establishing technological additives that increase the elastic-strength characteristics of rubber and its resistance to the action of aggressive hydrocarbon media. The composition of the rubber mixture to be studied included butadiene-nitrile rubber BNKS-28AMN, novoperoks BP-40, zinc monometacrylate, diaphene FP, acetononyl H, oligoester acrylates MGF-9 and TGM-3, carbon black filler P 803 and other ingredients. On lab rollers LB 320 150/150, rubber compound variants were prepared by mixing rubber with ingredients and processing aids. As technological additives were used lubstab-01, zinclet BB 222, dispersant Fl plus and oxanol CS-100. For the rubber mixture variants, the vulcanization characteristics on the MDR 3000 rheometer manufactured by Mon Tech were investigated. The rubber mixture was vulcanized in a two-storey hydraulic electrically heated press VP-400-2E at a temperature of 150 ° C for 30 min. Investigations of the elastic-strength properties of vulcanizates were carried out according to the existing standards for the rubber industry. The study of the thermo-aggressiveness of vulcanizates was carried out by determining the change in their elastic-strength properties after the thermal action of the standard liquid SZHR-1, as well as the change in mass after aging in a mixture of isooctane and toluene. As a result of the conducted studies it was found that the introduction of technological additives leads to an increase in the elastic-strength index of rubber by improving the dispersion of carbon black filler P 803 and other components of the mixture in the rubber matrix. The best elastic-strength characteristics and the smallest their change after exposure to aggressive hydrocarbonic fluids is characterized rubber containing zinkolet BB 222.Forcitation:Spiridonov I.S., Ushmarin N.F., Egorov E.N., Sandalov S.I., Kol'tsov N.I. Influence technological additives on properties of rubber based on butadiene-nitrile caoutchuc. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2017. V. 60. N 10. P. 53-57


2021 ◽  
Vol 0 (1) ◽  
pp. 23-27
Author(s):  
I. S. Nefyolov ◽  
◽  
N. I. Baurova ◽  

The effect of negative temperatures on strength characteristics of plastic component joints (hot gas welding, gluing, 3D-welding) made with the use of additive technologies has been examined. It has been found out that 3D-wlding allows one to produce joints with the highest strength properties. It was shown that low temperature values (–30 °С) did not have the negative influence on strength properties of ABS-plastic joints but even increased them as compared with analogues samples tested at the room temperature.


2014 ◽  
Vol 14 (1) ◽  
pp. 37-40 ◽  
Author(s):  
M. Holtzer ◽  
D. Drożyński ◽  
A. Bobrowski ◽  
W. Plaza

Abstract The results of investigations of moulding sands with an inorganic binder called GEOPOL, developed by the SAND TEAM Company are presented in the paper. Hardeners of various hardening rates are used for moulding sands with this binder. The main aim of investigations was determination of the influence of the hardening rate of moulding sands with the GEOPOL binder on technological properties of these sands (bending strength, tensile strength, permeability and grindability). In addition, the final strength of moulding sands of the selected compositions was determined by two methods: by splitting strength and shear strength measurements. No essential influence of the hardening rate on such parameters as: permeability, grindability and final strength was found. However, the sand in which the slowest hardener (SA 72) were used, after 1 hour of holding, had the tensile and bending strength practically zero. Thus, the time needed for taking to pieces the mould made of such moulding sand will be 1.5 - 2 hours.


1930 ◽  
Vol 3 (2) ◽  
pp. 340-341
Author(s):  
G. M. Carson

Abstract IN THE course of an extended research on various grades of carbon black, determinations of total moisture were made by an adaptation of an old method. The method used was similar to one described by Allen and Jacobs (1) for measuring water in tar. The chief difference in the present method is that small amounts of moisture in carbon blacks must be weighed, whereas the larger amounts in tar could be measured. The difficulties in weighing the evolved moisture are described in the ensuing method of determination. Five grams of carbon black were placed in a 500-cc. round-bottom flask with 25 to 35 cc. of dry xylene and 200 cc. of dry mineral oil. A short air condenser led to the bottom of a 25-cc. distilling flask, which in turn was connected to two or more calcium chloride tubes. The flask containing the sample was heated to 150-175° C. in an oil bath, a stream of dry nitrogen being passed through the apparatus. The water and xylene were distilled into the small distilling flask and thence, by warming in a water bath, into the calcium chloride tubes, the current of nitrogen being continued. It required but a few minutes to remove the water from the xylene, indicated by the disappearance of cloudiness, and the calcium chloride tubes were then connected directly to the nitrogen line and the gas was passed through until the tubes reached constant weight. ylene is not adsorbed by calcium chloride and nitrogen does not remove water from it at room temperature during the time required for the experiment. The increase in weight of the calcium chloride tubes is the amount of water in the sample of carbon black. The amount of water thus determined is considerably higher than the 105° C. oven loss in 5 hours, and indicates that most of the moisture is of the “bound” or “capillary” type.


1966 ◽  
Vol 39 (4) ◽  
pp. 1041-1052 ◽  
Author(s):  
Frederic J. Linnig ◽  
Edwin J. Parks ◽  
Robert D. Stiehler

Abstract Crystalline organic compounds containing a β-naphthyl group cause pronounced stiffening of rubber vulcanizates under certain conditions. When these materials are removed by extraction, the reinforcing effect vanishes. Reversibility of this effect indicates that the forces involved are not those associated with primary bonds. Reinforcement by at least one of these materials, PBNA, is obtained with vulcanizates made from various elastomers and vulcanizing agents, and is essentially independent of the state of cure. In some instances about five per cent of PBNA, the most effective of these, produces the same stiffness on first extension as 40 phr carbon black. Any PBNA dissolved in the rubber has no effect on stiffness. Thus, less than three per cent crystalline PBNA may produce an isotropic Young's modulus of about 20 kg/cm2 at room temperature. At higher concentrations of PBNA, strain continues to decrease but hardness does not change proportionally. The temperature coefficient of Young's modulus for PBNA reinforced rubber is negative, like that for vulcanizates containing carbon black. However, the increased solubility of PBNA with rising temperature makes quantitative determination of the temperature coefficient difficult. The PBNA-rubber structure is partly destroyed by repeated extensions to twice the original length. However after 5 extensions a substantial enhancement of modulus remains. Addition of PBNA to a rubber vulcanizate does not affect significantly the glass transition temperature. Though the reversible nature of reinforcement with PBNA strongly suggests a physical mechanism, the stiffening cannot be explained by existing theories of physical reinforcement.


Author(s):  
S. Mahajan

The evolution of dislocation channels in irradiated metals during deformation can be envisaged to occur in three stages: (i) formation of embryonic cluster free regions, (ii) growth of these regions into microscopically observable channels and (iii) termination of their growth due to the accumulation of dislocation damage. The first two stages are particularly intriguing, and we have attempted to follow the early stages of channel formation in polycrystalline molybdenum, irradiated to 5×1019 n. cm−2 (E > 1 Mev) at the reactor ambient temperature (∼ 60°C), using transmission electron microscopy. The irradiated samples were strained, at room temperature, up to the macroscopic yield point.Figure 1 illustrates the early stages of channel formation. The observations suggest that the cluster free regions, such as A, B and C, form in isolated packets, which could subsequently link-up to evolve a channel.


Author(s):  
R. M. Anderson ◽  
T. M. Reith ◽  
M. J. Sullivan ◽  
E. K. Brandis

Thin films of aluminum or aluminum-silicon can be used in conjunction with thin films of chromium in integrated electronic circuits. For some applications, these films exhibit undesirable reactions; in particular, intermetallic formation below 500 C must be inhibited or prevented. The Al films, being the principal current carriers in interconnective metal applications, are usually much thicker than the Cr; so one might expect Al-rich intermetallics to form when the processing temperature goes out of control. Unfortunately, the JCPDS and the literature do not contain enough data on the Al-rich phases CrAl7 and Cr2Al11, and the determination of these data was a secondary aim of this work.To define a matrix of Cr-Al diffusion couples, Cr-Al films were deposited with two sets of variables: Al or Al-Si, and broken vacuum or single pumpdown. All films were deposited on 2-1/4-inch thermally oxidized Si substrates. A 500-Å layer of Cr was deposited at 120 Å/min on substrates at room temperature, in a vacuum system that had been pumped to 2 x 10-6 Torr. Then, with or without vacuum break, a 1000-Å layer of Al or Al-Si was deposited at 35 Å/s, with the substrates still at room temperature.


Author(s):  
Fumio Watari ◽  
J. M. Cowley

STEM coupled with the optical system was used for the investigation of the early oxidation on the surface of Cr. Cr thin films (30 – 1000Å) were prepared by evaporation onto the polished or air-cleaved NaCl substrates at room temperature and 45°C in a vacuum of 10−6 Torr with an evaporation speed 0.3Å/sec. Rather thick specimens (200 – 1000Å) with various preferred orientations were used for the investigation of the oxidation at moderately high temperature (600 − 1100°C). Selected area diffraction patterns in these specimens are usually very much complicated by the existence of the different kinds of oxides and their multiple twinning. The determination of the epitaxial orientation relationship of the oxides formed on the Cr surface was made possible by intensive use of the optical system and microdiffraction techniques. Prior to the formation of the known rhombohedral Cr2O3, a thin spinel oxide, probably analogous to γ -Al203 or γ -Fe203, was formed. Fig. 1a shows the distinct epitaxial growth of the spinel (001) as well as the rhombohedral (125) on the well-oriented Cr(001) surface. In the case of the Cr specimen with the (001) preferred orientation (Fig. 1b), the rings explainable by spinel structure appeared as well as the well defined epitaxial spots of the spinel (001). The microdif fraction from 20A areas (Fig. 2a) clearly shows the same pattern as Fig. Ia with the weaker oxide spots among the more intense Cr spots, indicating that the thickness of the oxide is much less than that of Cr. The rhombohedral Cr2O3 was nucleated preferably at the Cr(011) sites provided by the polycrystalline nature of the present specimens with the relation Cr2O3 (001)//Cr(011), and by further oxidation it grew into full coverage of the rest of the Cr surface with the orientation determined by the initial nucleation.


2002 ◽  
Vol 721 ◽  
Author(s):  
Monica Sorescu

AbstractWe propose a two-lattice method for direct determination of the recoilless fraction using a single room-temperature transmission Mössbauer measurement. The method is first demonstrated for the case of iron and metallic glass two-foil system and is next generalized for the case of physical mixtures of two powders. We further apply this method to determine the recoilless fraction of hematite and magnetite particles. Finally, we provide direct measurement of the recoilless fraction in nanohematite and nanomagnetite with an average particle size of 19 nm.


2020 ◽  
Author(s):  
Keishiro Yamashita ◽  
Kazuki Komatsu ◽  
Hiroyuki Kagi

An crystal-growth technique for single crystal x-ray structure analysis of high-pressure forms of hydrogen-bonded crystals is proposed. We used alcohol mixture (methanol: ethanol = 4:1 in volumetric ratio), which is a widely used pressure transmitting medium, inhibiting the nucleation and growth of unwanted crystals. In this paper, two kinds of single crystals which have not been obtained using a conventional experimental technique were obtained using this technique: ice VI at 1.99 GPa and MgCl<sub>2</sub>·7H<sub>2</sub>O at 2.50 GPa at room temperature. Here we first report the crystal structure of MgCl2·7H2O. This technique simultaneously meets the requirement of hydrostaticity for high-pressure experiments and has feasibility for further in-situ measurements.


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