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1
Yardley, Adrian. "Cataloguing Rubbra." Musical Times 132, no. 1778 (April 1991): 177. http://dx.doi.org/10.2307/966126.
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Onderdonk, Julian, and Ralph Scott Grover. "The Music of Edmund Rubbra." Notes 51, no. 1 (September 1994): 152. http://dx.doi.org/10.2307/899209.
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Byron Adams. "Edmund Rubbra: Symphonist (review)." Notes 65, no. 2 (2008): 321–23. http://dx.doi.org/10.1353/not.0.0095.
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Pickard, John. "Generic Fusion in the 'Sinfonia Sacra': Redeeming Rubbra." Musical Times 142, no. 1877 (2001): 34. http://dx.doi.org/10.2307/1004575.
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Więckol-Ryk, Angelika, Maciej Thomas, and Barbara Białecka. "Improving the Properties of Degraded Soils from Industrial Areas by Using Livestock Waste with Calcium Peroxide as a Green Oxidizer." Materials 14, no. 11 (June 7, 2021): 3132. http://dx.doi.org/10.3390/ma14113132.
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Over the past years, the treatment and use of livestock waste has posed a significant problem in environmental engineering. This paper outlines a new approach to application of calcium peroxide (CaO2) as a green oxidizer and microbiocidal agent in the treatment of poultry manure. It also presents the application of pretreated waste in improvement of degraded soils in industrial areas. The CCD (Central Composite Design) and RSM (Response Surface Methodology) were employed for optimizing the process parameters (CaO2 concentration 1.6–8.4 wt %, temperature 5.2–38.8 °C and contact time 7–209 h). The analysis of variance (ANOVA) was used to analyze the experimental results, which indicated good fit of the approximated to the experimental data (R2 = 0.8901, R2adj = 0.8168). The amendment of CaO2 in optimal conditions (8 wt % of CaO2, temperature 22 °C and contact time 108 h) caused a decrease in bacteria Escherichia coli (E. coli) in poultry manure from 8.7 log10 CFU/g to the acceptable level of 3 log10 CFU/g. The application of pretreated livestock waste on degraded soils and the studies on germination and growth of grass seed mixture (Lollum perenne—Naki, Lollum perenne—Grilla, Poa pratensis—Oxford, Festuca rubbra—Relevant, Festuca rubbra—Adio and Festuca trachypylla—Fornito) showed that a dose of 0.08 g of CaO2 per 1 gram of poultry manure induced higher yield of grass plants. The calculated indicators for growth of roots (GFR) and shoots (GFS) in soils treated with poultry manure were 10–20% lower compared to soils with amended CaO2. The evidence from this study suggests that CaO2 could be used as an environmentally friendly oxidizer and microbiocidal agent for livestock waste.
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Hayeemasae, Nabil, Kannika Sahakaro, and Hanafi Ismail. "Maleated Natural Rubber Compatibilized Natural Rubber/Halloysite Nanotubes Composites." Polymer Korea 44, no. 5 (September 30, 2020): 596–602. http://dx.doi.org/10.7317/pk.2020.44.5.596.
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Chang, Mingfeng, Yixing Zhang, Jianzhong Pei, Jiupeng Zhang, Min Wang, and Fugui Ha. "Low-Temperature Rheological Properties and Microscopic Characterization of Asphalt Rubbers Containing Heterogeneous Crumb Rubbers." Materials 13, no. 18 (September 16, 2020): 4120. http://dx.doi.org/10.3390/ma13184120.
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Asphalt rubbers mixed with untreated and plasticized crumb rubbers and a compounding coupling agent were investigated in this study. The low-temperature rheological properties of asphalt rubbers at different aging levels were tested using a dynamic shear rheometer (DSR). An interconversion between linear viscoelastic material functions was used to obtain converted evaluation indexes for the asphalt rubbers at low temperatures. Lastly, the physicochemical characteristics and the microscopic morphology of the asphalt rubbers were evaluated using Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM), respectively. In conclusion, the storage moduli of the asphalt rubbers containing heterogeneous crumb rubbers increased with the plasticized crumb rubber content and the aging level. The converted relaxation moduli were consistent with the change trend of the storage moduli, and the relaxation rate decreased as the plasticized crumb rubber content and the aging level increased. The process of mixing the base asphalt with crumb and plasticized crumb rubbers was physical blending, and the effect of aging on the absorption peak change of asphalt rubber with plasticized crumb rubbers was less than that of asphalt rubber with ordinary crumb rubbers. Aging deteriorated the blending between the crumb rubber and the base asphalt, and a distinct interface appeared between the crumb rubber and the base asphalt. The particle cores of the plasticized crumb rubber in the asphalt rubber were difficult to maintain. Furthermore, as the plasticized crumb rubber content increased, more fine particles stripped off the plasticized crumb rubber after aging.
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Sokolova, M. D., A. F. Fedorova, and V. V. Pavlova. "Research of Influence of Plasticizers on the Low-Temperature and Mechanical Properties of Rubbers." Materials Science Forum 945 (February 2019): 459–64. http://dx.doi.org/10.4028/www.scientific.net/msf.945.459.
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In this paper, influence of new plasticizers on the mechanical and low-temperature properties of rubbers is studied. The subjects of the research are rubbers based on BNKS-18 butadiene-nitrile rubber and Hydrin T-6000 epichlorohydrin rubber (ECHR). As used plasticizers: DINP (diisononylphthalate), TOTM (trioctyltrimellitate), DOA (dioctyladipate), Alphaplast (complex plasticizer based on esters of organic alcohols and acids). For identification the efficiency, rubbers with the studied plasticizers compared with standard rubber, in which plasticizers have not introduced, as well as with rubber in which a widely used industrial plasticizer DOF (dioktilphthalate) was added. Research of the mechanical properties of rubbers based on BNKS-18 showed that the introduction of plasticizers leads to an increase in elasticity and a slight decrease in the strength of rubbers and on the contrary for rubbers based on ECHR. Low-temperature properties of rubbers with all studied plasticizers have an increased level in comparison with standard rubber. In rubber based on BNKS-18, the highest values of the coefficient of frost resistance at-45°C are observed with the introduction of plasticizers Alphaplast and DOA, an increase in the index compared to standard rubber is more than 50%. The same plasticizers have shown the greatest contribution to the increase in frost resistance of rubbers based on ECHR.
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Ismail, Muhammad Sopyan, Aldi Nur Rahman, Aulia Hanna Farhatin, Malikhatun Khasanah, and Diah Nugraheni. "Rubble BricQ (Briket Limbah Daun Karet) Sebagai Inovasi Bahan Bakar Alternatif Masa Kini." JURNAL Al-AZHAR INDONESIA SERI SAINS DAN TEKNOLOGI 6, no. 1 (March 31, 2021): 57. http://dx.doi.org/10.36722/sst.v6i1.635.
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<p><strong>Rubber leaf waste is often found in rubber plantations and is considered of no value to the community. Rubble BricQ (Rubber Leaf Waste Briquettes) is an innovative alternative fuel today by utilizing rubber leaf waste that does not pollute the environment and the price is affordable. Briquettes can replace some of the uses of kerosene and LPG gas such as food processing, drying, burning, and heating. The purpose of this study was to find out how to make Rubble BricQ (Rubber Leaf Waste Briquettes) as an alternative fuel today which is packaged in video form due to the Covid-19 pandemic. This research phase begins by collecting the materials needed to make a Rubble BricQ (Rubber Leaf Waste Briquette) video through digital searches (internet). The result of this research is to know how to make Rubble BricQ (Rubber Leaf Waste Briquettes) as an alternative fuel today through video. Therefore, it can be concluded that Rubble BricQ is made by burning rubber leaf waste into charcoal, pounding it until smooth, adding tapioca flour, molding, drying it to dry, and the results can be used immediately.</strong></p><p><strong><em>Keywords</em></strong><em> - Briquettes, Rubber Leaves, Rubble BricQ.</em></p>
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Dulina, O. A., A. D. Tarasenko, A. M. Bukanov, and A. A. Ilyin. "THE INFLUENCE OF THE METHOD OF RUBBER ISOLATION FROM LATEX ON THE PROPERTIES OF ELASTOMERIC MATERIALS BASED ON BUTADIENE-NITRILE RUBBERS." Fine Chemical Technologies 12, no. 4 (August 28, 2017): 85–90. http://dx.doi.org/10.32362/2410-6593-2017-12-4-85-90.
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The properties of butadiene-nitrile rubbers obtained by various methods of synthesis and isolation from latex and rubbers based on them were studied in the article. The surface free energy of samples was determined using the Owens, Wendt, Rabel and Kaelble method. It was shown that the surface energy of elastomeric materials is affected 1) by non-rubber components, the content and nature of which are determined by the method of obtaining and isolating rubber from latex and 2) by the number of nitrile groups in the rubber macromolecule. The kinetics of vulcanization of rubber compounds based on the investigated rubbers has been studied. It was shown that rubber compounds based on rubbers containing a residual emulsifier are vulcanized longer. Elastic-strength properties were studied, and it was concluded that rubbers based on butadienenitrile rubbers synthesized by various methods with the same content of bound nitrilacrylic acid have different physico-mechanical properties and cannot be used interchangeably without changing the formulation and technological parameters of their processing.
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Uchiyama, Y. "The Effect of the Environment on the Friction and Wear of Blended Rubber." Tire Science and Technology 22, no. 1 (January 1, 1994): 2–18. http://dx.doi.org/10.2346/1.2139533.
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Abstract The friction and wear of rubber are properties that are affected by the environment, especially by the oxygen in the air. Natural rubber (NR) is most sensitive to air, butadiene rubber (BR) is scarcely affected by the presence of air, while styrene butadiene rubber (SBR) is intermediate compared to NR and BR. Both the abrasive and fatigue wear rates of NR and BR blends are known to decrease by increasing the BR content. To reduce the wear rates of NR vulcanizates in the air, SBR was blended with NR. In severe rubbing experiments against abrasive cloths, the wear rate of the NR-SBR blends slightly decreased by increasing the SBR content. The NR-SBR blends showed considerable reduction in wear under fatigue wear conditions against metal gauze. Similar experiments were also conducted for SBR-BR blends. Blending with BR showed a substantial reduction in wear, especially in fatigue wear. When NR-BR, NR-SBR, and SBR-BR blends were rubbed against metal gauze in vacuum, the friction and wear of these three blended rubbers was lower in vacuum than in room air. It is concluded that the wear resistance of the blended rubber is affected by its sensitivity to air as well as by the mechanochemical properties of the blends under fatigue wear conditions.
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Le Cam, Jean-Benoit. "A REVIEW OF VOLUME CHANGES IN RUBBERS: THE EFFECT OF STRETCHING." Rubber Chemistry and Technology 83, no. 3 (September 1, 2010): 247–69. http://dx.doi.org/10.5254/1.3525684.
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Abstract Elastomeric materials are subjected to significant change in volume during their deformation. This paper proposes to review the change in volume of stretched rubber and to highlight why volume change can be considered as a relevant mechanical quantity to characterize rubbery materials in terms of microstructure evolution. The first part of the present review examines experimental measurements of volume change reported from the end of the 19th century until now. The second part reports the models proposed to predict the change in volume of stretched rubbers. These are formulated for small deformations. Some of them account for the decrease in volume due to crystallization.
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Isayev, Avraam I., Tian Liang, and Todd M. Lewis. "EFFECT OF PARTICLE SIZE ON ULTRASONIC DEVULCANIZATION OF TIRE RUBBER IN TWIN-SCREW EXTRUDER." Rubber Chemistry and Technology 87, no. 1 (March 1, 2014): 86–102. http://dx.doi.org/10.5254/rct.13.87926.
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ABSTRACT Ultrasonic devulcanization of tire rubber particles of 10 and 30 meshes by means of a new ultrasonic twin-screw extruder was investigated. The ultrasonic amplitude and devulcanization temperature were varied at a fixed frequency of 40 kHz. The die pressure and ultrasonic power consumption during devulcanization were recorded. The degree of devulcanization was investigated by measuring the cross-link density, gel fraction, and revulcanization behavior. Rubber of 30 mesh exhibited a lower die pressure and higher degree of devulcanization than that of rubber of 10 mesh. Because of the higher level of devulcanization and lower viscosity of devulcanized rubbers at higher amplitudes, the temperature of devulcanized rubbers at the die was reduced with an increase of the ultrasonic amplitude. Generally, the torque at the start of curing and maximum torque on the curing curve measured during revulcanization is higher for rubber of 10 mesh and rubbers devulcanized at a lower temperature. Rheological properties of devulcanized and revulcanized rubbers and mechanical properties of revulcanizates were measured. The complex viscosity of devulcanized and revulcanized rubbers of both meshes as a function of frequency exhibited a power-law behavior, with the power-law index being 0.06 for devulcanized rubbers and 0.02 for revulcanized rubbers. The consistency index of devulcanized and revulcanized rubbers was higher for rubber of 10 mesh; however, both rubbers showed a higher consistency index at a lower temperature. Cole–Cole plots, cross-link density, and gel fraction of devulcanized and revulcanized rubbers, revulcanization behavior, and modulus of revulcanizates separated in two distinct groups based on the level of devulcanization and effect on molecular structure of devulcanized rubber. Revulcanizates with a greater degree of devulcanization exhibited a higher elongation at break, whereas those with a lower degree of devulcanization exhibited higher strength and modulus. Revulcanizates of rubber of 30 mesh exhibited a consistently higher elongation at break. The normalized gel fraction versus normalized cross-link density was described by a unique function independent of the processing conditions and rubber particle size.
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Tavio and Usman Wijaya. "Comparative behavior of local hyperelastic lowgrade rubbers for low-cost base isolation." MATEC Web of Conferences 276 (2019): 01001. http://dx.doi.org/10.1051/matecconf/201927601001.
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As the second largest rubber producer in the world, Indonesia has a very potential opportunity to support the development of rubber base isolation. Various grades of rubber are produced by the local rubber manufacturers starting from the low to high grade rubbers. In the study, the local rubbers were also compared to the rubbers from another developing country, e.g. India. The laboratory test results used to develop the suitable constitutive model for hyperelastic material and then compared to the hyperelastic model of Shahzad et al. Several tests on the local low-grade rubbers have been conducted, namely the uniaxial tensile, planar shear, and equibiaxial tensile tests. From the tests, it can be concluded the behavior of the local low-grade rubber can be fitted with the Ogden model different from the characteristic of rubber tested by Shahzad et al. which was fitted with the Yeoh model.
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Kovaleva, L. A., N. Ya Ovsyannikov, and A. A. Zuev. "Change of electrical characteristics of rubber in the process of “swelling–deswelling”." Fine Chemical Technologies 15, no. 6 (January 13, 2021): 56–66. http://dx.doi.org/10.32362/2410-6593-2020-15-6-56-66.
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Objectives. The main indicator that determines electrical conductivity of rubbers is specific volumetric electrical resistance (ρv ). The purpose of this work is to investigate changes in this indicator during swelling and deswelling of electrically conductive rubbers. When considering the swelling process of rubbers in liquid media at a molecular level, an analogy of this process with mechanical deformation of the material is drawn and common features and differences of these processes are revealed.Methods. For rubber compositions based on paraffinate and alkyl sulfonate nitrile butadiene rubbers, the degree of their swelling and the change in linear dimensions in heptane and in gasoline grades 80, 92, and 95 were determined. The ρ v value was determined by a potentiometric method: the initial value was measured after temperature control of rubbers for 1 h at 120°C, and the second measurement was carried out after these rubbers were swollen in the solvents for 48 h, followed by drying at 20°C to a constant weight and repeated temperature control under the same conditions. Using an IR Fourier spectrometer, spectra of the solvents used were obtained before and after identification of the investigated rubber samples in them.Results. It was shown that the type of rubber and solvent used influence the degree of rubber swelling. Rubber compositions based on natural rubbers with a large amount of attached acrylonitrile, obtained in the presence of an alkyl sulfonate emulsifier, have the highest resistance to swelling. The effect of the used solvent on the change in the degree of swelling is determined by its affinity for rubber and the presence of polar additives that increase the octane number of gasoline. It was established that the linear change of the samples upon swelling in the indicated solvents varies according to the length and thickness of the samples. Results show that depending on the type of rubber used and the degree of its filling, the described rubber processing technology leads to a decrease in the ρ v value by 2 to 20 times. The greatest effect of ρ v reduction is observed in low-filled rubber compositions based on paraffinate nitrile rubbers. The spectra of the frustrated total internal reflection of the solvents after their interaction with the studied rubbers show that particulate extraction of dibutyl phthalate, which was used as a plasticizer in rubber compounding, takes place as a result of rubber swelling.Conclusions. The proposed method of rubber processing reduces the ρ v value by removing dibutyl phthalate from the studied rubbers and forming a more developed carbon–elastomer structure. Furthermore, it solves the problem of the negative effect of the plasticizer on the ρ v value of rubber without excluding it from the rubber composition.
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Sakdapipanich, Jitladda T., Kanjanee Nawamawat, and Seiichi Kawahara. "Characterization of the Large and Small Rubber Particles in Fresh Hevea Latex." Rubber Chemistry and Technology 75, no. 2 (May 1, 2002): 179–85. http://dx.doi.org/10.5254/1.3544971.
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Abstract The rubbers from small and large rubber particles were separated from the serum and cream phases of centrifuged fresh Hevea latex, respectively. The small rubber particles (SRP) consist of rubber molecules showing a unimodal molecular weight distribution (MWD), with a peak-top value falling between the two peak values of the bimodal MWD observed in rubbers from the large rubber particles (LRP). The rubbers in LRP from mature trees and SRP from seedlings are polyisoprene molecules terminated by phospholipids comprising branching points, while those in SRP from mature trees are presumed to be linear molecules containing no phospholipid terminal. The serum rubber was found to be soft and viscous rubber differing from the cream rubber containing in LRP. Thus, it can be presumed that the particle size of rubber latex is an important parameter influencing the MW, MWD and physical properties of Hevea rubber.
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Shipcova, O. N., Yu O. Andriasyan, D. A. Menyak, K. V. Sukhareva, I. A. Mikhailov, and A. A. Popov. "MECHANOCHEMICAL MODIFICATION OF SILOXANE RUBBER (SKTV) IN THE PRESENCE OF A CHLORINE AND FLUOR-CONTAINING REAGENT." IZVESTIA VOLGOGRAD STATE TECHNICAL UNIVERSITY, no. 5(240) (May 19, 2020): 54–58. http://dx.doi.org/10.35211/1990-5297-2020-5-240-54-58.
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The paper is devoted to investigation of mechanochemical halide modification of siloxane rubber (SKTV) using chlorine and fluorine-containing modifiers. Rubber compounds based on modified and original unmodified, siloxane rubbers were prepared. Rheological and curing properties of obtained rubbers were examined. In the established time optimum vulcanizates were obtained and their physical, mechanical and some special properties were studied. In order to study the molecular mobility of the modified rubbers ESR-spectroscopy study was carried out. The analysis of molecular mobility of modified rubbers has shown previously unknown regularities of mechanochemical halide modification of siloxane rubber using chlorine and fluorine-containing modifiers. The rheological and curing properties of the initial and modified rubbers were investigated. The application fields of halogen modified rubbers was determined.
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Gusev, S. V., Yu O. Andriasyan, D. S. Voropaev, K. V. Sukhareva, I. A. Mikhailov, and A. A. Popov. "MECHANOCHEMICAL MODIFICATION OF NITRILE-BUTADIENE RUBBER IN THE PRESENCE OF A CHLORINE-CONTAINING REAGENT." IZVESTIA VOLGOGRAD STATE TECHNICAL UNIVERSITY, no. 5(240) (June 19, 2020): 59–63. http://dx.doi.org/10.35211/1990-5297-2020-5-240-59-63.
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This work is devoted to study of halide mechanochemical modification of nitrile-butadiene rubber (BNCS-18AN) with a chlorine-containing reagent. In previous studies, the optimal parameters for modification were established. The modification was carried out in a laboratory rubber mixer. The obtained halogen-containing rubbers were investigated using ESR spectroscopy. Rubber compounds based on obtained chlorinated butadiene-nitrile rubbers (CNBR), were prepared and their tensile stress-strain properties and curing characteristics were investigated. Vulcanization of rubber compounds was carried out under the established optimal conditions. Physical and mechanical properties of the rubbers were determined. Subsequent studies showed the most probable regularities of the mechanochemical halide modification of nitrile butadiene rubber (BNCS-18AN) with a chlorine-containing modifier (CHCl) in a rubber mixer.
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Gunaydin, Abdullah, Clément Mugemana, Patrick Grysan, Carlos Eloy Federico, Reiner Dieden, Daniel F. Schmidt, Stephan Westermann, Marc Weydert, and Alexander S. Shaplov. "Reinforcement of Styrene Butadiene Rubber Employing Poly(isobornyl methacrylate) (PIBOMA) as High Tg Thermoplastic Polymer." Polymers 13, no. 10 (May 17, 2021): 1626. http://dx.doi.org/10.3390/polym13101626.
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A set of poly(isobornyl methacrylate)s (PIBOMA) having molar mass in the range of 26,000–283,000 g mol−1 was prepared either via RAFT process or using free radical polymerization. These linear polymers demonstrated high glass transition temperatures (Tg up to 201 °C) and thermal stability (Tonset up to 230 °C). They were further applied as reinforcing agents in the preparation of the vulcanized rubber compositions based on poly(styrene butadiene rubber) (SBR). The influence of the PIBOMA content and molar mass on the cure characteristics, rheological and mechanical properties of rubber compounds were studied in detail. Moving die rheometry revealed that all rubber compounds filled with PIBOMA demonstrated higher torque increase values ΔS in comparison with rubber compositions without filler, independent of PIBOMA content or molar mass, thus confirming its reinforcing effect. Reinforcement via PIBOMA addition was also observed for vulcanized rubbers in the viscoelastic region and the rubbery plateau, i.e. from −20 to 180 °C, by dynamic mechanical thermal analysis. Notably, while at temperatures above ~125 °C, ultra-high-molecular-weight polyethylene (UHMWPE) rapidly loses its ability to provide reinforcement due to softening/melting, all PIBOMA resins maintained their ability to reinforce rubber matrix up to 180 °C. For rubber compositions containing 20 phr of PIBOMA, both tensile strength and elongation at break decreased with increasing PIBOMA molecular weight. In summary, PIBOMA, with its outstanding high Tg among known poly(methacrylates), may be used in the preparation of advanced high-stiffness rubber compositions, where it provides reinforcement above 120 °C and gives properties appropriate for a range of applications.
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Kohjiya, Shinzo, and Yuko Ikeda. "Reinforcement of General-Purpose Grade Rubbers by Silica Generated In Situ." Rubber Chemistry and Technology 73, no. 3 (July 1, 2000): 534–50. http://dx.doi.org/10.5254/1.3547604.
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Abstract The use of the sol—gel process on general-purpose grade rubbers is reviewed in the absence or presence of silane coupling agents. The sol—gel reactions of tetraethoxysilane (TEOS) in epoxidized natural rubber (ENR), styrene—butadiene rubber (SBR) or butadiene rubber (BR) vulcanizates produced silica generated in situ. This silica was found to be a good reinforcing agent by investigating tensile and dynamic mechanical properties and morphology observation by transmission electron microscopy (TEM). The amount of silica formed was limited by the degree of swelling of the rubber vulcanizate by TEOS which was the precursor of the silica. However, the dispersion of silica generated in situ was better than conventionally added silica due to its formation in place. Also, it was noted that the diameter distribution of in situ silica was monodispersed. Silane coupling agents, such as mercaptosilane, aminosilane, and bis(3-triethoxysilylpropyl) tetrasulfide, were compounded in the vulcanizates and their effects on silica generated in situ were evaluated. Their effects were significant. The dispersion of the silica in the rubbery matrix became better and the particle size became smaller and monodispersed, as observed by TEM, which improved mechanical properties. The superior properties of silica generated in situ have been studied further to elucidate the mechanism of reinforcement.
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Shirazi, M., and J. W. M. Noordermeer. "FACTORS INFLUENCING REINFORCEMENT OF NR AND EPDM RUBBERS WITH SHORT ARAMID FIBERS." Rubber Chemistry and Technology 84, no. 2 (June 1, 2011): 187–99. http://dx.doi.org/10.5254/1.3570531.
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Abstract Among short fiber reinforced composites, those with rubbery matrices have gained great importance due to the advantages they have in processing and low cost, coupled with high strength. These composites combine the elastic behavior of rubbers with strength and stiffness of fibers. Aramid fibers have been chosen because of their significantly higher modulus and strength, compared to other commercial fibers. Compounds based on NR and EPDM are prepared. Short aramid fibers with different kinds of surface treatments, standard finish, and resorcinol formaldehyde latex (RFL)-coating result in different rubber–fiber interfaces. The reinforcing effect of these short aramid fibers is characterized by mechanical and viscoelastic experiments, and by studying the fracture surfaces with electron microscopy techniques. Related to the fiber coating and rubber curing system, sulfur- or peroxide-based, different reinforcement mechanisms are observed, where the combination of peroxide-cured EPDM with RFL-treated fibers is the only case showing clear signs of chemical adhesion. In all other combinations there are only indications of mechanical interactions of the fibers with the rubber matrices, due to bending/buckling of fibers, dog-bone shaped fiber ends, and surface roughness due to the RFL-coating.
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Zhang, Tengfei, Jie Su, Yuanjie Shu, Fei Shen, and Liaoliang Ke. "Fretting Wear Behavior of Three Kinds of Rubbers under Sphere-On-Flat Contact." Materials 14, no. 9 (April 23, 2021): 2153. http://dx.doi.org/10.3390/ma14092153.
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Rubbers are widely used in various fields as the important sealing materials, such as window seal, door seal, valve, pump seal, etc. The fretting wear behavior of rubbers has an important effect on their sealing performance. This paper presents an experimental study on the fretting wear behavior of rubbers against the steel ball under air conditions (room temperature at 20 ± 2 °C and humidity at 40%). Three kinds of rubbers, including EPDM (ethylene propylene diene monomer), FPM (fluororubber), and NBR (nitrile–butadiene rubber), are considered in experiments. The sphere-on-flat contact pattern is used as the contact model. The influences of the displacement amplitude, normal force, frequency, and rubber hardness on the fretting wear behavior are discussed in detail. White light profiler and scanning electron microscope (SEM) are used to analyze the wear mechanism of the rubber surface. The fretting wear performances of three rubbers are compared by considering the effect of the displacement amplitude, normal force, frequency, and rubber hardness. The results show that NBR has the most stable friction coefficient and the best wear resistance among the three rubbers.
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Shafranska, Olena, Dean C. Webster, Bret J. Chisholm, Sean McFarlane, and Janice Tardiff. "Modified Soybean Oil as a Processing Oil for Styrene-Butadiene Rubber Tire Tread Compounds." Tire Science and Technology 47, no. 4 (October 1, 2019): 280–91. http://dx.doi.org/10.2346/tire.18.470105.
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ABSTRACT Soybean oil (SBO) was modified with polystyrene via a radical graft polymerization reaction for use as a processing oil in tire tread compounds. Poly(styrene-butadiene)/polybutadiene rubber compounds with silica and carbon black, containing different processing oils including naphthenic oil (NO), aromatic oil (AO), SBO, and polystyrene-modified SBO (SBO-PS), were formulated, vulcanized, and tested. The curing behavior, mechanical properties, and dynamic properties were investigated. The cure test results showed that all SBO-based rubbers had a shorter scorch time and cure window than the NO- and AO-based rubbers. The tensile tests demonstrated that partial and complete replacement of NO with SBO led to reduced tensile modulus but increased elongation of rubber. For the rubbers compounded with SBO-PS and with a 50/50 mixture of NO/SBO-PS, tensile strength and elongation were higher than for the NO-based rubber. The same tendency was observed when SBO-PS–based rubbers were compared with SBO- and AO-based rubbers. SBO-PS–based rubbers demonstrated better tensile properties than AO-based rubbers and far better properties than SBO-based rubbers. In the tear resistance test and durometer hardness test, SBO-PS contained rubbers that showed similar properties to NO-containing rubber. The dynamic mechanical analysis of SBO-PS–containing rubbers demonstrated that use of this compound in tire treads is expected to improve both rolling resistance and wet traction when compared with an AO-based rubber. The modification of SBO with grafted PS is a promising method of making processing oil, which can replace petroleum-based processing oils with bio-based renewable oils in tire tread compounds while improving their properties.
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Sedykh, V. A., O. V. Karmanova, and E. V. Koroleva. "Modification of nitrile butadiene rubber at the stage of its allocation." Proceedings of the Voronezh State University of Engineering Technologies 80, no. 3 (December 17, 2018): 323–29. http://dx.doi.org/10.20914/2310-1202-2018-3-323-329.
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Search for additives that increase the wear resistance of rubbers is relevant. It is known that the introduction of hollow corundum microspheres (NCM) into rubber reduces the wear of rubber products. The uniform distribution of small amounts of microspheres in rubber by traditional "dry" mixing in a rubber mixer or on rollers is difficult. Microspheres were introduced into rubber at the stage of its separation from latex. The work consisted in the selection of thickeners capable of holding the NSM in rubber latex SCN-18SNT at the stage of its coagulation, and evaluation of physical and mechanical properties of rubbers in the presence of NCM. The retention capacity of thickeners of polyacrylamide (PAA), carboxymethylcellulose (CMC) and polyvinyl alcohol (PVA) was determined. Thickened latex was coagulated in the presence of microspheres with polymeric coagulant and sulfuric acid. When filling the polymer with microspheres, it is preferable to use a PAA thickener. The yield of microspheres in rubber using thickeners PAA, CMC and PVA was 71.1, 66.5 and 38.7% , respectively. The physico-mechanical characteristics of rubbers based on SKN-18SNT in the presence of microspheres introduced both as a "dry" method in rubber and at the stage of its isolation from latex are determined. The presence of microspheres in an amount of 4.4-4.7% by weight. on rubber, did not affect the hardness and elasticity of rebound rubbers. It has been confirmed that the presence of microspheres, especially those introduced from the latex rubber release stage, provides an increase in abrasion resistance. In turn, the presence of microspheres in rubber with traces of polyacrylamide provided an increase in the resistance of rubbers to tearing, the modulus at 100 and 200% elongation with a decrease in the elongation at break.
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Shilov, М. А., S. V. Fomin, A. A. Britova, and P. V. Korolev. "Investigation of Physical and Mechanical Properties of Rubbers Reinforced by Carbon Nanostructured Components." Liquid Crystals and their Application 20, no. 4 (December 29, 2020): 93–98. http://dx.doi.org/10.18083/lcappl.2020.4.93.
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The work presents investigation results of physical and mechanical properties of rubber mixtures based on SKI-3 and SKS-30-ARKM-15 rubbers reinforced with hybrid filler carbon black/carbon nanotubes (CB/CNT). Elasticity, hardness and strength were measured according to standard procedures presented in GOST. The content of the carbon nanotubes in rubber mixtures was 0,5 wt. %. parts per 100 wt. parts of rubber. According to experiments, it was found that the introduction of CB/CNT masterbatches into the structure of both investigated rubbers reduces their elasticity and increases Shore A hardness. During uniaxial tension of the tested rubbers, it was found that the presence of the nanostructured CB/CNT filler in the rubber structure leads to an increase in the nominal strength for SKI-3-based rubber by 19,6 %, and on SKS-30-ARKM-15 by 22,5 %. Therefore, the use of CB/CNT nanostructures as a rubber filler is a promising method of improving rubber performance characteristics.
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Mukhin, V. V., Natalia N. Petrova, V. V. Portnyagina, A. L. Fedorov, and A. V. Baisheva. "Investigation of the Plasticizer Content Effects on the Operability of the Epichlorohydrin Rubber Based Elastomeric Material during Full-Scale Test under Cold Climate Conditions and Hydrocarbon Medium Influence." Materials Science Forum 945 (February 2019): 417–21. http://dx.doi.org/10.4028/www.scientific.net/msf.945.417.
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Sealing rubbers used in the climatic conditions of the Far North and the Arctic, based on butadiene-nitrile rubbers contain significant amounts of plasticizers, which increase their frost resistance. They lose low-temperature and operational properties when they contact with the hydrocarbon medium due to intensive plasticizer washing out. Zeon Hydrin T6000 epichlorohydrin rubber, has a low glass transition temperature (Tg = -60 °C) and resistance to aggressive media. The model rubber was developed that minimally meets the requirements for sealing rubbers. Samples were exposed in oil, for 2 years, in climate of Yakutsk, the Republic of Sakha (Yakutia), Russia. The climate is characterized by significant average daily temperature fluctuations with a transition through the 0 °C and low temperatures below-60 °C. For comparison, simultaneously rubbers based on butadiene-nitrile rubbers was investigated. Every two months, the main parameters were measured: swelling degree, tensile strength, elongation, frost resistance coefficient for elastic recovery after compression at-50 °C and-30 °C, compression set and plasticizer content by means of IR spectroscopy. Model rubber showed excellent frost resistance while retaining the other properties, regardless of the plasticizer content, while rubber based on butadiene-nitrile rubber irreversibly lost low-temperature properties in the first months. Similar results were obtained earlier in the study propylene oxide rubber produced in Russia (Tg = -74°C). During full-scale exposure, a small dependence of its low-temperature characteristics on the amount of plasticizer in the elastomeric material was also revealed. Thus, epichlorohydrin rubber Hydrin T6000 can be used as a sealing rubber.
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Shevchenko, O. B., S. М. Zybailo, K. M. Sukhyi, V. O. Holovenko, and D. V. Popytailenko. "Estimation of resistance of engine rubber sealants to influence of mixed diesel fuel." Voprosy Khimii i Khimicheskoi Tekhnologii, no. 5 (October 2021): 118–23. http://dx.doi.org/10.32434/0321-4095-2021-138-5-118-123.
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The sorption-diffusion properties of rubbers in contact with fuels containing methyl esters of fatty acids derived from non-food raw materials have been studied. The hypothesis was advanced according to which there is a dependence of oil resistance of rubbers on their solubility parameter of butadiene-nitrile rubber. The properties of standard oil-resistant rubbers based on butadiene nitrile rubbers of SKN-18 and SKN-40 brands were compared with those of SKN-18-based rubber and Byprene 110 chloroprene-based rubber, to each of them 30% of the plasticized polyvinyl chloride was added. It was found that the contact with the fuel composition, which consists of 70% diesel fuel and 30% methyl esters of fatty acids made from technical sunflower oil, has the strongest destructive effect on all experimental samples of rubber except for rubber-based rubber of SKN-40 brand. It was determined that SKN-40-based rubber, which is characterized by the maximum solubility parameter, is the most stable in relation to fuel compositions containing methyl esters of fatty acids of various origins. Based on the analysis of experimental data, the recommendations were given for the use of SKN-40-based rubber for the manufacture of car engine seals within the global trend to increase the share of alternative components in diesel fuels.
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Efimovskiy, Egor G., Nikolay F. Ushmarin, Sergey I. Sandalov, Nikolay I. Kol'tsov, Alexey G. Golikov, Natalia A. Kostikova, Oksana I. Korneeva, Maria M. Antonova, and Dmitry I. Klimov. "Study of the possibility of using diafen FP, sulfenamide C and N,N’-dithiodimorpholine of domestic production in rubber mixtures instead of imported analogues." Butlerov Communications 57, no. 2 (February 28, 2019): 123–29. http://dx.doi.org/10.37952/roi-jbc-01/19-57-2-123.
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The article presents the results of a study of various rubber compounds based on rubbers containing, in the composition, made by FGUP GosNIIOHT diafen FP, sulfenamide C and N,N'-dithiodimorpholine instead of imported analogues. Rubber compounds were made on a laboratory rubber mixer SKI-3L with Intermix rotors. After a day at room temperature, the rubber mixtures were vulcanized on a vacuum compression machine of column type a firm Panstone 3RT. The main technological indicators of rubber mixtures after their manufacture on the rolls were: ductility, ring modulus and density. These indicators characterize the processability of rubber mixtures in the manufacture of products from them. For the obtained vulcanizates, the elastic-deformation properties (conditional tensile strength, relative elongation at break, Shore A and ISO hardness, bond strength with metal at tearing, and abrasion resistance) were determined by standard methods. To assess the performance properties of rubbers, changes in conditional tensile strength, relative elongation at break, hardness, volume and mass after rubbers aging in corrosive media, as well as relative residual deformation of compression, temperature limit of brittleness and frost resistance were determined. The possibility of using diaphene FP, sulfenamide C and N,N'-dithiodimorpholine made by FSUE "GosNIIOHT" as part of various rubber mixtures instead of imported analogs is shown. The obtained rubbers according to the technological, elastic-deformation and operational properties comply with the requirements. These rubbers can be used for the manufacture of rubber-technical products with a special set of elastic-deformation and performance properties, and domestic ingredients manufactured by the Federal State Unitary Enterprise GosNIIOHT can be introduced into production.
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Abdikarimov, Malik N., R. Kh Turgumbayeva, S. S. Sagintaeva, R. Mussabekov, and A. K. Yamanbekova. "Polymer Compositions Based on Rolling and Liquid Carboxy-Containing Rubbers." Key Engineering Materials 816 (August 2019): 345–49. http://dx.doi.org/10.4028/www.scientific.net/kem.816.345.
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The processes of pyrolysis and combustion of rubber-based synthetic rubbers were studied. Determined that Teflon (polytetrafluoroethylene) helps reduce the rate of burning rubber in half, from 0.25 mm/s to 0.14 m/s based on a mixture of isoprene and butadiene-styrene rubbers
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Tahir, Muhammad, Gert Heinrich, Nasir Mahmood, Regine Boldt, Sven Wießner, and Klaus Stöckelhuber. "Blending In Situ Polyurethane-Urea with Different Kinds of Rubber: Performance and Compatibility Aspects." Materials 11, no. 11 (November 2, 2018): 2175. http://dx.doi.org/10.3390/ma11112175.
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Specific physical and reactive compatibilization strategies are applied to enhance the interfacial adhesion and mechanical properties of heterogeneous polymer blends. Another pertinent challenge is the need of energy-intensive blending methods to blend high-tech polymers such as the blending of a pre-made hard polyurethane (-urea) with rubbers. We developed and investigated a reactive blending method to prepare the outstanding blends based on polyurethane-urea and rubbers at a low blending temperature and without any interfacial compatibilizing agent. In this study, the polyurethane-urea (PUU) was synthesized via the methylene diphenyl diisocyanate end-capped prepolymer and m-phenylene diamine based precursor route during blending at 100 °C with polar (carboxylated nitrile rubber (XNBR) and chloroprene rubber (CR)) and non-polar (natural rubber (NR), styrene butadiene rubber (sSBR), and ethylene propylene butadiene rubber (EPDM)) rubbers. We found that the in situ PUU reinforces the tensile response at low strain region and the dynamic-mechanical response up to 150 °C in the case of all used rubbers. Scanning electron microscopy reveals a stronger rubber/PUU interface, which promotes an effective stress transfer between the blend phases. Furthermore, energy filtered transmission electron microscopy (EFTEM) based elemental carbon map identifies an interphase region along the interface between the nitrile rubber and in situ PUU phases of this exemplary blend type.
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Tsou, Andy H., Ilan Duvdevani, and Kenneth O. McElrath. "Co-Continuity and Ozone Resistance of Bims Compounds." Rubber Chemistry and Technology 76, no. 2 (May 1, 2003): 318–25. http://dx.doi.org/10.5254/1.3547745.
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Abstract A co-continuous blend of a high ozone resistant rubber with high diene rubbers, or with a mixture of high diene rubbers, can provide a rubber blend that is both ozone resistant and wear and scuff resistant. High diene rubbers have excellent wear and scuff resistances, but are prone to ozone damage. The high ozone resistant rubbers are rubbers that have saturated backbone after vulcanization, such as BIMS. However, depending on the co-continuous morphology, not all co-continuous blends of an ozone resistant rubber with other rubbers are ozone resistant. In this study, a co-continuity index was proposed to measure the co-continuity morphology of 50/50 BIMS/GPR blends. GPR represents a general-purpose rubber and is a mixture of NR and BR in this study. It was found that BIMS compounds having their co-continuity indices greater than 0.7 are ozone resistant. These ozone-resistant compounds were prepared by first adding GPR followed by adding small N351 CB fillers, as compared with the other large N660 CB used in this work. Thus, smaller CB filler first presence in GPR appears to enhance GPR/BIMS phase compatibility during mixing with later added BIMS leading to strong intermixing between co-continuous phases.
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Efimov, Konstantin V. "Study of the properties of water-swelling rubber containing gums and extelint." Butlerov Communications 62, no. 4 (April 30, 2020): 72–76. http://dx.doi.org/10.37952/roi-jbc-01/20-62-4-72.
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It is known that the main role in water-swellable sealing elements belongs to rubber, the properties of which depend on the nature of the rubbers and functional ingredients used. Water-swellable sealing elements are mainly made from rubbers based on acrylate, chloroprene and nitrile butadiene rubbers using various hydrophilic additives: starch derivatives, cellulose, polyvinyl alcohol and various oligomeric resins. However, after sufficiently long contact with water, some additives are washed out and the sealing properties of the sealing elements are lost. Among the promising insoluble and limited water-swellable additives, sodium polyacrylate should be distinguished. Using it as part of rubbers together with soluble water-swellable additives will allow preserving the sealing properties of the sealing elements by filling it with the pores formed when washing water-soluble swellable additives from rubbers. In this regard, in this work, the effect of guar and xanthan gums together with extelint fiber on the properties of water-swelling rubber based on a combination of nitrile butadiene BNKS-18AMN, chloroprene neoprene W, acrylate nipole AR22 and butadiene SKD caoutchoucs with sulfuric vulcanizing system, was studied. The rubber mixture was prepared by mixing rubbers with ingredients on laboratory rolls LB 320 160/160. The rheological characteristics of the rubber composition were studied on an MDR 3000 Basic rheometer at 150 °C. Standard samples of the rubber mixture were vulcanized at a temperature of 150 ° C for 30 minutes in a curing press type P-V-100-3RT-2-PCD. The main properties of the vulcanizates were determined according to the standards applicable in the rubber industry. It is shown that the introduction of gums with extelite into the rubber mixture leads to a change in its rheological parameters. Vulcanizates that contain gums are characterized by lower values of conditional tensile strength and rebound elasticity, but larger elongation at break and degree of swelling in distilled and formation water compared to the vulcanizate of the base rubber mixture.
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Chou, Liang Hsiung. "On Improvements of Rubberized Concrete with Organosulfur Compounds." Advanced Materials Research 156-157 (October 2010): 1459–62. http://dx.doi.org/10.4028/www.scientific.net/amr.156-157.1459.
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Crumb rubbers have been investigated as additives to concrete and promising results have been observed. Organosulfur compounds from a petroleum-refining factory were used to modify the surface properties of crumb rubbers. The intermolecular interaction forces between cement hydration products (C-S-H) and rubber crumbs were measured directly by an atomic force microscope (AFM) equipped with a colloid probe. Experimental data indicate that crumb rubber surface is more hydrophilic after the treatment with organosulfur compounds and the intermolecular interaction forces between C-S-H and rubber increase with the treatment of crumb rubbers with organosulfur compounds. Furthermore, these increased interaction forces lead to an increased concrete strength.
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Polmanteer, Keith E. "Silicone Rubber, Its Development and Technological Progress." Rubber Chemistry and Technology 61, no. 3 (July 1, 1988): 470–502. http://dx.doi.org/10.5254/1.3536197.
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Abstract This paper has described silicone rubber, its first commercial development in 1944, and its technological progress since then. Pioneering research on silicon opened the door to the development of silicone polymers and silicone rubber. The substitution of two methyl groups on silicon was present in the first examples of silicone rubber and still is the predominant organic group in commercial silicone rubber today. Silicone rubbers have filled a need in the marketplace because of their combination of unusual properties not found in other rubbers. The alternating inorganic main-chain atoms of silicon and oxygen, and the two pendant organic groups, primarily methyl, provide strong chain bonds, backbone flexibility, ease of side-group rotation, and low “inter” and “intra” molecular forces. This molecular makeup and properties thereof are primarily responsible for the observed performance of silicone rubbers. Many significant advances in silicone rubber have been discussed in chronological sequence to trace its history from 1944 to 1987.
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Shim, Sang E., and A. I. Isayev. "Ultrasonic Devulcanization of Precipitated Silica-Filled Silicone Rubber." Rubber Chemistry and Technology 74, no. 2 (May 1, 2001): 303–16. http://dx.doi.org/10.5254/1.3544952.
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Abstract This investigation involves the recycling of precipitated silica-filled silicone rubber using a continuous ultrasonic reactor. The processing conditions utilized in devulcanization of the filled systems were similar to those in our previous work on unfilled systems. Significant differences were observed in devulcanization of unfilled and filled systems. A decrease in gel fraction and crosslink density was sufficient for devulcanized silica-filled silicone rubber to be reprocessed and revulcanized. The cure behavior of silicone rubber and the mechanical properties of virgin, and revulcanized rubber were measured. Results showed that unfilled silicone rubbers gave no change in vulcanizate mechanical properties after revulcanization. However, in the filled rubbers there was a decrease in the mechanical properties of revulcanizates. In order to achieve an improvement in the properties, devulcanized filled rubbers were blended with virgin filled rubber in various proportions. The obtained results indicated a considerable enhancement of the performance characteristics of these blend vulcanizates.
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Thi Thuong, Nghiem, Phan Trung Nghia, and Seiichi Kawahara. "Factors influencing green strength of commercial natural rubber." Green Processing and Synthesis 7, no. 5 (October 25, 2018): 399–403. http://dx.doi.org/10.1515/gps-2018-0019.
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Abstract The factors influencing the green strength of commercial solid rubbers were investigated in the present study through characterization of commercial natural rubber (NR). Various solid commercial rubbers such as standard Vietnam rubber (SVR10), standard Indonesia rubber (SIR10), India standard natural rubber (ISNR10), ribbed smoked sheets (RSS3), and FNR (commercial Sumitomo Rubber) were used as a source. Purification of the samples was carried out through acetone extraction and purified samples were characterized by nuclear magnetic resonance (NMR) and Fourier-Transform infrared spectroscopy. Degradation was found for SVR10, ISNR10, and SIR10 but not for RSS3 and FNR through the assignment of 13C-NMR signals. Acetone extraction was found to improve the green strength of commercial NR due to the removal of impurities. Linked fatty acids and proteins contributed to the upturn of stress at small strain. However, the network structure of degraded rubbers had an insignificant role in enhancing the green strength of commercial NR.
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Mat Desa, Mohd Shaiful Zaidi, Azman Hassan, Agus Arsad, and Nor Nisa Balqis Mohammad. "Mechanical and Thermal Properties of Rubber Toughened Poly(Lactic Acid)." Advanced Materials Research 1125 (October 2015): 222–26. http://dx.doi.org/10.4028/www.scientific.net/amr.1125.222.
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The effect of rubber toughening on mechanical and thermal properties of poly (lactic acid) (PLA) was investigated by using three types of rubbers; natural rubber (NR), epoxidized natural rubber (ENR) and core-shell rubber (CSR). The PLA/rubber blends were prepared by melt blending in a counter-rotating twin-screw extruder, where the rubber content for all blends was kept at 5 wt%. It was found that the addition of the rubbers increased the impact strength for all blends as compared to pure PLA. On the other hand, all PLA/rubber blends showed notable decrease of Young’s modulus especially for PLA/NR blend which decreased by 72% than pure PLA. Similarly, significant decrease of tensile strength was also observed for all PLA/rubber blends. PLA/ENR blend showed a morebalance mechanical properties with fairly significant improvement of impact strength and moderate decrease of tensile strength, Young’s modulus and elongation at break. In general, PLA/NR blend showed the highest overall impact strength, while the PLA/CSR showed the highest tensile strength and Young’s modulus among the blends. Thermal analysis revealed that the Tg of PLA decreased with incorporation of the three types of rubbers with NR showing the largest decrease. This study indicates that NR, ENR and CSR are effective in enhancing toughness of PLA
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Rajeev, R. S., and S. K. De. "Crosslinking of Rubbers by Fillers." Rubber Chemistry and Technology 75, no. 3 (July 1, 2002): 475–510. http://dx.doi.org/10.5254/1.3547679.
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Abstract Oxygen containing chemical groups on the carbon black surface can react with the carboxyl groups of XNBR, or epoxy groups of ENR, or chlorosulfonated groups of CSM, during high temperature molding of the rubber-filler mixtures. This leads to crosslinking of the rubber phase. The extent of crosslinking increases if the carbon black surface is oxidized, the concentration of the reactive groups of the rubber increases, or a suitable silane coupling agent is incorporated in the rubber-filler mixtures. Similarly, high temperature molding of the XNBR-precipitated silica, ENR-precipitated silica, CSM-precipitated silica, and CR-ferrite mixtures leads to crosslinking of the rubber phases, even in the absence of conventional rubber vulcanizing agents. XNBR-ZnO mixture on high temperature molding also produces crosslinked rubbers consisting of ionic crosslinks. During mixing stage, the reactive fillers interact with the polar rubbers leading to formation of high bound rubber, presumably through hydrogen bond formation. During high temperature molding of the rubber-filler mixtures for a prolonged time, the reactive groups on the filler surface chemically react with the functional groups of the rubber chains leading to crosslinks of the rubber phase. This is evident from the rise in the rheometric torque of the rubber-filler mixture and marked changes in properties of the mixture on high temperature molding. The properties in many instances are similar to that obtained in the case of rubbers crosslinked by conventional vulcanizing agents. Infrared spectroscopy has been used to identify the chemical structures at the filler-rubber interface formed during crosslinking of the rubber by the filler.
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Isayev, A. I., J. Chen, and A. Tukachinsky. "Novel Ultrasonic Technology for Devulcanization of Waste Rubbers." Rubber Chemistry and Technology 68, no. 2 (May 1, 1995): 267–80. http://dx.doi.org/10.5254/1.3538741.
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Abstract A novel patented process and several reactors have been developed for devulcanization of waste rubbers. The technology is based on the use of the high power ultrasonics. The ultrasonic waves of certain levels in the presence of pressure and heat rapidly break up the three-dimensional network in crosslinked rubbers. The devulcanized rubber can be reprocessed, shaped and revulcanized in much the same way as a virgin rubber. The first laboratory reactor has been scaled up to pilot-plant level by the National Feedscrew and Machining, Inc. Various devulcanization experiments were carried out with model styrene-butadiene rubber (SBR) and with ground rubber tire (GRT). Curing behavior, Theological properties, and structural characteristics of rubbers devulcanized at various processing conditions were studied, as well as mechanical properties of revulcanized rubber samples. A possible mechanism of the devulcanization is discussed. The performed measurements indicate that the rubbers are partially devulcanized, and the devulcanization process is accompanied by certain degradation of the macromolecular chains. In spite of these observations, the processing conditions are identified at which the retention of the mechanical properties is found to be good. A further work is in progress to find the optimal conditions of devulcanization and to improve the selectivity of the process towards breaking up the chemical network only.
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Nguyen Trong, Quang, Hung Dang Viet, Linh Nguyen Pham Duy, Chuong Bui, and Duong Duc La. "Detailed Study on the Mechanical Properties and Activation Energy of Natural Rubber/Chloroprene Rubber Blends during Aging Processes." Journal of Chemistry 2020 (November 17, 2020): 1–7. http://dx.doi.org/10.1155/2020/7064934.
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Selection of a suitable thermal aging process could render desirable mechanical properties of the rubbers or blended rubbers. In this work, the effect of the aging processes on the mechanical properties and activation energies of natural rubbers (NR) and NR/chloroprene rubbers (CR) blends with low CR contents (5–10%) was investigated. Three aging processes including heat aging (at 110°C for 22 hours), mechanical aging (under dynamic loading to 140% strain for 16000 cycles), and complex aging (heat and mechanical aging) were studied. The results revealed that the compatibility of CR in natural rubber matrix had a significant effect on the dynamic properties of the blended rubber and negligible effect on the static properties. The changes in activation energies of the blended rubber during aging processes were calculated using Arrhenius relation. The calculated changes (ΔUc, ΔUd, and ΔUT) in activation energies were consistent with the results of mechanical properties of the blended rubber. Interestingly, the change in activation energies using complex aging conditions (ΔUc) was mostly equal to the total changes in activation energies calculated separately from heat aging (ΔUT) and mechanical aging (ΔUd) conditions. This indicates that, in complex aging conditions, the heat and dynamic loading factors act independently on the properties of the blended rubber.
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Ikeda, Yuko, Preeyanuch Junkong, Takumi Ohashi, Treethip Phakkeeree, Yuta Sakaki, Atitaya Tohsan, Shinzo Kohjiya, and Katrina Cornish. "Strain-induced crystallization behaviour of natural rubbers from guayule and rubber dandelion revealed by simultaneous time-resolved WAXD/tensile measurements: indispensable function for sustainable resources." RSC Advances 6, no. 98 (2016): 95601–10. http://dx.doi.org/10.1039/c6ra22455e.
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Efimov, Konstantin V., Lyudmila Yu Tsareva, Nikolay F. Ushmarin, and Nikolay I. Koltsov. "Influence of magnesium hydrosilicate on the properties plantar rubber." Butlerov Communications 61, no. 1 (January 31, 2020): 91–95. http://dx.doi.org/10.37952/roi-jbc-01/20-61-1-91.
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The properties of rubber products are determined by the nature and content of caoutchoucs, vulcanizing systems and other ingredients. Among them, fillers play an important role. The most common fillers are carbon black and silicas. Recently, in connection with the increasing operational requirements for rubber products, additives of special fillers began to be introduced into rubber mixtures. Among them, silicates are of practical interest, the use of which allows not only to reduce the cost, but also to give qualitatively new useful physical and mechanical properties to rubbers. Improving the physical and mechanical properties of rubbers directly depends on the particle size of the fillers. Fillers with a smaller particle size have a larger surface area and have a significant effect on the physical and mechanical properties of rubbers. The highly developed surface of powdered magnesium hydrosilicate suggests its use as a filler for rubber compounds. In this regard, it is of interest to study the effect of magnesium hydrosilicate on the properties of rubbers. This article explored the possibility of using magnesium hydrosilicate in plantar rubber based on a combination of nitrile butadiene SKN-4055, methyl styrene butadiene SKMS-30ARK and isoprene SKI-3 caoutchoucs. The rheometric properties were investigated for the rubber mixture, and the physical and mechanical properties, hardness, resistance to thermal aging and the action of aggressive media were determined for vulcanizates. As a result of the studies, it was found that the best rheometric, physico-mechanical and operational properties are possessed by the vulcanizate of the rubber compound, in which the silicon-acid filler of rossil 175 was partially replaced by magnesium hydrosilicate. This rubber can be used in the production of oil and petrol resistant soles of rubber shoes.
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Karambar, Smitha, and Stefan Tenbohlen. "Compatibility Study of Silicone Rubber and Mineral Oil." Energies 14, no. 18 (September 17, 2021): 5899. http://dx.doi.org/10.3390/en14185899.
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In this study, three types of silicone rubbers, namely, insulative silicone rubber, conductive silicone rubber and silicone rubber with conductive as well as insulative layers are investigated for their compatibility with mineral oil. Mineral oil with different silicone rubber samples is thermally aged at 130 °C for 360 h, 720 h and 1080 h and at 23 °C, 98 °C and 130 °C for 360 h. At the end of each ageing interval, mineral oil and oil-impregnated silicone rubbers are investigated for their dielectric properties. Aged mineral oil samples are investigated for their moisture content, breakdown voltage, colour number, dissolved gases and total acid number, whereas solid insulation samples are investigated for their moisture content. Additionally, pressboard samples in mineral oil and mineral oil without any solid insulation materials are also aged under the same conditions and are investigated for their dielectric properties. From the obtained results, it can be assessed that the presence of carbon particles in conductive silicone rubber negatively impacts the dielectric properties of mineral oil. Among the investigated silicone rubbers, the insulative silicone rubber exhibits good compatibility with mineral oil and a strong potential for being used in mineral oil.
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Sarkar, Preetom, and Anil K. Bhowmick. "Sustainable rubbers and rubber additives." Journal of Applied Polymer Science 135, no. 24 (September 20, 2017): 45701. http://dx.doi.org/10.1002/app.45701.
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Bandyopadhyay, S., S. Dasgupta, N. Mandal, S. L. Agrawal, S. K. Mandot, R. Mukhopadhyay, A. S. Deuri, and Suresh C. Ameta. "Use of Recycled Tyre Material in Natural Rubber based Tyre Tread Cap Compound: Part I (with Ground Crumb Rubber)." Progress in Rubber, Plastics and Recycling Technology 21, no. 4 (November 2005): 299–317. http://dx.doi.org/10.1177/147776060502100404.
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For both environmental and economic reasons, there is a continuing broad-based interest in the recycling of scrap rubber and therefore in the development of recycling technologies. In the present work three different sizes of mechanically ground Indian crumb rubbers were used in a natural rubber (NR) based tyre tread cap compound. Varying doses of crumb rubber were used as an additional compounding ingredient. The minimum torque and Mooney viscosity values were marginally increased with increasing dose and mesh size of crumb rubber. In a Rubber Process Analyser (RPA) study, the Payne effect before curing was marginally higher for compounds containing crumb rubber, while, after curing a comparable Payne effect was observed with respect to the control compound without having crumb rubber. A marginal deterioration in tensile strength, fatigue to failure and abrasion properties was observed. At all levels of usage, the 100 mesh size ground crumb rubber retained the properties better than other lower mesh size crumb rubbers.
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Ushmarin, Nikolay F., Evgeniy N. Egorov, and Nikolay I. Kol'tsov. "FROST-RESISTANT RUBBER ON BASE OF COMBINATION OF BUTADIENE-NITRILE AND HYDRIN RUBBERS." IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENIY KHIMIYA KHIMICHESKAYA TEKHNOLOGIYA 60, no. 8 (August 29, 2017): 60. http://dx.doi.org/10.6060/tcct.2017608.5474.
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The influence of hydrin rubbers on the plastic-elastic, rheometric, physical-mechanical properties and frost resistance of oil-and-petrol resistant rubber mixture of B-14 type was studied. The study was carried out with the purpose of selecting the composition of the rubber mixture, which is resistant to low temperatures and has increased operational properties. The composition of the test rubber mixture with a sulfur vulcanization system consisted of butadiene-nitrile rubber BNKS-18AMN (copolymer of butadiene and acrylonitrile) and hydrin rubbers T-3000 and T-6000 (copolymers of epichlorohydrin, ethylene oxide, propylene oxide and allyl glycidyl ether), diphenylguanidine, zinc oxide, Agidol-2, technical carbon P 803, dibutyl sebacate and other ingredients. Rubber mixture was prepared by mixing caoutchoucs with ingredients on lab rolls LB 320 150/150. For the rubber mixture variants, the elastomeric properties on the viscosimeter MV 3000 and the vulcanization characteristics on the rheometer MDR 3000 of firm «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 40 min. Studies of the elastic-strength properties of rubber were carried out in accordance with the standards existing for the rubber industry. The frost resistance of rubber was investigated by determining the temperature limit of brittleness and by of method differential scanning calorimetry. The study of thermo-aggression resistance of vulcanizates was carried out by determining the change in their elastic-strength properties after prolonged thermal exposure to air and standard liquid SZHR-1, as well as changes in volume and mass after aging in technical oil AMG-10. As a result of the research it was established that the rubber mixture based on the combination of BNKS-18AMN and T-6000 rubbers can be used for the manufacture of frost-resistant rubber products and sealing elements for oil and gas industries that can work at elevated temperatures with improved elastic-strength and operational properties.Forcitation:Ushmarin N.F., Egorov E.N., Koltsov N.I. Frost-resistant rubber on base of combination of butadiene-nitrile and hydrin rubbers. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2017. V. 60. N 8. P. 60-64.
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Chudzik, Joanna, Dariusz M. Bieliński, Michael Bratychak, Yuriy Demchuk, Olena Astakhova, Marcin Jędrzejczyk, and Grzegorz Celichowski. "Influence of Modified Epoxy Resins on Peroxide Curing, Mechanical Properties and Adhesion of SBR, NBR and XNBR to Silver Wires. Part I: Application of Monoperoxy Derivative of Epoxy Resin (PO)." Materials 14, no. 5 (March 9, 2021): 1320. http://dx.doi.org/10.3390/ma14051320.
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The research was aimed at checking the effect of monoperoxy derivative of epoxy resin (PO) on the possibility of rubber crosslinking and a subsequent adhesion of the modified rubber to silver wires. Three of the commonly industrially used rubbers were selected for the study: styrene-butadiene rubber (SBR), acrylonitrile-butadiene rubber (NBR) and carboxylated acrylonitrile-butadiene rubber (XNBR), together with the popular, commercially available Epidian 6 epoxy resin, subjected to the functionalization. An improvement in the adhesion of rubbers to silver wires was observed when using the modified resin. In some cases, an improvement in the mechanical properties of the rubber was observed, especially when the resin was used for crosslinking together with dicumyl peroxide (DCP). Crosslinking synergy between dicumyl peroxide and the modified resin could be observed especially in the case of PO applied for peroxide curing of SBR and NBR.
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Grigoryeva, O., A. Fainleib, O. Starostenko, I. Danilenko, N. Kozak, and G. Dudarenko. "Ground Tire Rubber (GTR) Reclamation: Virgin Rubber / Reclaimed GTR (RE)Vulcanizates." Rubber Chemistry and Technology 77, no. 1 (March 1, 2004): 131–46. http://dx.doi.org/10.5254/1.3547806.
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Abstract Thermochemically partially devulcanized ground tire rubber (GTRD) was revulcanized in compositions with different virgin rubbers. Two different devulcanizing groups (mixture of softeners) with and without processing oil have been used for GTR treatment. As virgin rubbers methylstyrene/butadiene (SBR), isoprene (IR) and butadiene (BR) rubbers or their combinations were selected. They were cured by using sulfur, tetramethyl thiuram disulfide (TMTD) or peroxide based vulcanizing systems. The Rubber/GTRD (re)vulcanizates with the GTRD content from 20 to 80 wt. % have been prepared and studied. Vulcanization by sulfur system was found as preferable for IR/GTRD formulations. The best properties for BR/GTRD and SBR/GTRD vulcanizates were reached with the vulcanization system based on TMTD. The co-curing in the interphase between the GTRD particles and the surrounding rubber matrix improves the mechanical properties of (re)vulcanizates obtained. The reclaimed GTRD studied has been used successfully in standard formulations for tires instead of the part of virgin rubbers.
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Syayleva, M. V., A. M. Bukanov, K. A. Zvezdenkov, and V. N. Voloshin. "THE STUDY OF THE PROPERTIES OF VULCANIZATES BASED ON ETHYLENE VINYL ACETATE RUBBERS WITH DIFFERENT CONTENT OF VINYL ACETATE UNITS." Fine Chemical Technologies 13, no. 3 (June 28, 2018): 79–85. http://dx.doi.org/10.32362/24106593-2018-13-3-79-56.
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The article studies the structure and properties of ethylene vinyl acetate rubbers and the influence of the vinyl acetate (VA) units content in the rubber on the technological, physical-mechanical, operating and electrical properties of vulcanizates. The results of the study prove that the distinctive feature of ethylene vinyl acetate rubbers compared to other rubbers is their thermoplastic properties and low viscosity. Besides, the high resistance to ozone, heat and oil resistance and good mechanical properties of vulcanizates based on them make this type of polymer materials very promising for the creation of modern products. It is shown that the values of elasticity modulus, strength, elongation and tear resistance are increased with increasing VA units content in the rubber. Besides, swelling in hydrocarbon media decreases. Vulcanizates containing 40-45% of VA have satisfactory electrical characteristics and good moisture resistance and can be used as the base insulating rubber. Vulcanizates with a high content of vinyl acetate units (60-70%) have high oil and heat resistance. Therefore, their use in rubber compounds for cable jackets is most effective. The study of the properties of ethylene vinyl acetate rubbers and their vulcanizates allowed to develop formulations of insulating and jacket rubbers and to determine the most promising areas of their application for modern cable products of special purpose in the petrochemical, aerospace, transport and shipbuilding industries.
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Sokolova, M. D., A. F. Fedorova, and M. L. Davydova. "Influence of 6PPD Stabilizer on Climatic Stability of Rubbers Based on Butadiene-Nitrile and Epichlorohydrin Rubbers." Materials Science Forum 945 (February 2019): 433–37. http://dx.doi.org/10.4028/www.scientific.net/msf.945.433.
Full textAbstract:
The present paper outlines the results of full-scale tests of climatic stability and the study of resistance to the action of hydrocarbon media of rubbers based on BNKS-18-18 (butadiene-nitrile rubber) and Hydrin T6000 epichlorohydrin rubber containing one of 6PPDstabilizerwith an aromatic amine moiety widely used in synthetic rubbers. Samples are exposed in an open ground under natural conditions of exposure to climatic external factors of Yakutsk in the Republic of Sakha (Yakutia), as well as in the oil environment of Talakanskoye field and I-50A hydraulic fluid in an unheated room. Such indexes of the samples as conditional tensile strength, elongation at rupture, hardness and degree of swelling are measured to determine the resistance of rubbers to aging after the first, third, and sixth months of exposing. The results of the study reveal the contribution of 6PPD stabilizer in maintaining the stability of the physical and mechanical properties of BNKS-18: rubber containing 6PPD has less property changes both in the open air and in hydrocarbon media compared to rubber without a stabilizer. It should be noted that the oil environment is the most aggressive environment, the swelling of rubbers in oil leads to a significant reduction in strength due to a decrease in intermolecular interaction.6PPD stabilizer occurred less effective for the rubber based on Hydrin T6000: changes in properties of the samples containing the stabilizer are larger than those of the samples without the stabilizer. However, unlike BNKS-18-18-based rubber, the swelling of rubber based on Hydrin T6000 led to the greatest stability of the physical and mechanical properties in the oil environment compared to the open air and hydraulic fluids.