Elastomer Blends — Improved Strength Properties of Uncured Rubber Compounds

1977 ◽  
pp. 51-73
Author(s):  
Emil M. Friedman ◽  
Richard G. Bauer ◽  
Diego C. Rubio
Author(s):  
O. V. Karmanova ◽  
S. G. Tikhomirov ◽  
E. V. Lintsova ◽  
L. V. Popova

Studies of experimental adhesion modifiers based on a mixture of fatty acids from the production of light vegetable oils. The properties of rubber compounds and their vulcanizates obtained using experimental adhesion promoters KK with cobalt content from 7.5 to 16.5% are investigated. The plastic-elastic and vulcanization properties of the properties of breaker rubber compounds based on polyisoprene, the physical and mechanical properties of breaker rubbers and the bond strength in the “rubber-brass-plated steel cord system” were studied. When testing belt rubbers containing experienced adhesion promoters or an imported analog of Manobond 680C, the following features were revealed. The plasticity of the prototypes was in the range of 0.2-0.4. This indicates satisfactory processing properties. The Mooney viscosity of the prototypes was lower than that of the production sample. The use of experienced adhesion promoters instead of the analogue (Manobond 680C) increases the resistance to scorching. On the basis of the analysis of elastic-strength properties, it was found that in terms of the conditional tensile strength, the prototypes were inferior to the serial ones. However, rubbers containing the KK-12, KK-13.5, KK-15 promoters met the control standards. The tensile elongation at break of the experimental rubbers is higher than that of the serial sample. This may indicate the formation of a more uniform cure network in the presence of the test products. When testing rubber-metal-hard composites, it was noted that, under normal conditions, the experienced adhesion promoters have advantages over Manobond 680C. However, at elevated temperatures, under conditions of salt and steam-air aging, they are slightly inferior to Manobond 680C. It has been established that the experimental adhesion promoters provide the required set of technical properties of belt rubbers with a CO2 + content of 12–16.5% wt. Thus, it is possible to recommend the adhesion promoters KK 12, KK-13.5, KK 15 for practical use in the composition of belt rubber compounds. This will allow replacing a foreign-made product and reducing the cost of production.


2017 ◽  
Vol 44 (11) ◽  
pp. 15-20
Author(s):  
G.V. Moiseevskaya ◽  
G.I. Razd'yakonova ◽  
A.A. Petin

The aim of this work was to produce a new filler for polymers in which a low surface activity is combined with a high degree of structure and functionalisation of the surface, which will bring the processing properties of filled rubber mixes closer to the properties of rubber mixes with channel carbon black. The oxidation of specimens of low-dispersion, highly structured carbon black of grade OMCARB S820 was carried out using aqueous solutions of hydrogen peroxide of different concentration. Using a combination of methods, including X-ray diffraction analysis (D8 Advance diffractometer; Bruker, Germany) and transmission electron microscopy (JEM 2100 electron microscope; JEOL, Japan), we assessed the physicochemical properties and the form and the number of oxygen-containing groups (carboxyl, phenolic, lactone) on the surface of a particle of oxidised S820 in comparison with carbon black K354 (produced by the Khazar Chemical Plant, Turkmenistan) and semi-active furnace black N550 (produced by Omsktekhuglerod). The rheological characteristics (MDR 3000 vibrorheometer and MV 3000 viscometer; MonTech, Germany) and the physicomechanical characteristics (tensometer; Shimadzu, Japan) of rubber mixes filled with these blacks and of rubber compounds based on natural rubber were determined. The dynamic properties of the rubber compounds and the glass transition temperatures were determined on a DMA 242D instrument (Netzsch, Germany). Comparative data on the temperature dependence of the mechanical loss tangent (tg δ)of the rubber compounds showed that at temperatures of −60 and +60°C the greatest differences are possessed by rubber compounds with K354. At intermediate temperatures, the tg δ values for rubber compounds with the different fillers are similar. The new carbon black was advantageous with respect to the strength properties and dynamic characteristics of the rubber compounds, retaining the unique properties of composites filled with channel black.


Author(s):  
Д. Куделин ◽  
D. Kudelin ◽  
Т. Несиоловская ◽  
T. Nesiolovskaya ◽  
А. Ветошкин ◽  
...  

The most important task of the rubber industry is the continuous improvement of the quality, reliability and durability of products, including rubber membranes, which are widely used in the automotive, aviation, machine tool, chemical and other industries. Membranes in most cases are operated in difficult loading conditions, which leads to a variety of zones and the nature of potential damage that occurs during their operation. At the same time, when developing a new rubber compounds for membranes, most often the standard methods for determining the mechanical characteristics of rubbers are used, most of which involve testing the material under simple uniaxial tension-compression and do not take into account structural changes in the material during loading. In this work, a study of structural changes in the membranes under loading in a complex stressed state, which was realized by indenting the rubber membrane with a spherical indenter, was conducted. Structural changes were evaluated by hydrostatic weighing. It has been established that in the complex stressed state of rubber based on crystallizing IR rubber, there is no distinct advantage over rubber based on amorphous SBR rubber. Indentation suppresses orientation processes in rubbers based on IR crystallizing rubber, which leads to a significant decrease in their strength properties.


Author(s):  
O. A. Dulina ◽  
A. D. Tarasenko ◽  
A. M. Bukanov ◽  
A. A. Ilyin

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.


Author(s):  
А.А. Дьяконов ◽  
С.А. Тапыев ◽  
А.А. Охлопкова ◽  
С.А. Слепцова ◽  
Н.Н. Петрова ◽  
...  

Применение резинотехнических изделий в крайних условиях Севера ставит ряд научно-технических проблем, связанных с их надежностью и безотказностью. Основной причиной выхода из строя техники вовремя эксплуатации при низких отрицательных температурах является потеря работоспособности уплотнительных резин по причине низкой морозостойкости. Одним из способов решения данной проблемы является разработка резиновых смесей на основе двух или более каучуков, обладающих высокимизначениями морозо- и агрессиво- стойкости. В работе приведены результаты исследования эластомеров на основе комбинации изопренового каучука марки СКИ-3 и бутадиен-нитрильного каучука марки БНКС-18. В результате проведённых исследований установлено, что при разных соотношениях каучуков СКИ-3 и БНКС-18 в резиновой смеси происходит изменение упруго-прочностных свойств эластомеров, стойкости к углеводородным средам, модуля упругости, твердости, плотности, остаточной деформации сжатия и износостойкости. При исследовании на дифференциально-сканирующем калориметре были выявлены две температуры стеклования у резин на основе комбинации каучуков. При помощи электронного микроскопа были получены снимки в объеме образцов, на которых наблюдается фазовая морфология резин, которая в зависимости от соотношения каучуков в смеси более характерна для бутадиен-нитрильного или изопренового каучуков. Также отмечено, что поверхность трения резины на основе БНКС-18 обладает наиболее шероховатойструктурой по сравнению с резиной с большим содержанием каучука СКИ-3. The use of rubber products in the extreme conditions of the North creates a number of scientific and technical problems associated with their trustworthiness and reliability. The main reason of equipment failure during operation at low negative temperatures is the performance loss of sealing rubbers due to low frost resistance. One of the ways to solve this problem is the development of rubber compounds based on two or more types of rubber with high values ​​of frost and aggression resistance. This article presents research results of elastomers based on a combination of isoprene rubber IR and nitrile butadiene rubber NBR. As a result, it was discovered that at different ratios of IR and NBR rubbers in a rubber compound, there is a change in the elastic-strength properties of elastomers, resistance to hydrocarbon media, elastic modulus, hardness, density, residual compression deformation and wear resistance. In the research of differential scanning calorimeter, two glass transition temperatures were identified as rubbers based on a combination of rubber. Using electronic microscope, images were obtained in the volume of samples, which is the phase morphology of rubbers is observed, which is depending on ratio of rubber in the mixture is more specific for nitrile butadiene or isoprene rubber. It was also noted that the friction surface of rubber based on NBR has the roughest structure compared to rubber with a high content of IR rubber.


2021 ◽  
Vol 899 ◽  
pp. 239-244
Author(s):  
Larisa Yuryevna Zakirova

The article investigates the effect of vulcanizing systems of different activity on the vulcanization and elastic-strength properties of rubber compounds based on ethylene-propylene rubber Keltan . Were taken vulcanizing systems: a mixture of organic peroxide, sulfur and sulfenamide accelerator (1); a mixture of organic peroxide, sulfur and dithiodimorpholine (2); a mixture of organic peroxide, sulfur and thiuram accelerator (3); sulfur and sulfenamide accelerator (4). The vulcanization characteristics (maximum and minimum torques; times of onset, optimum and reaching the maximum speed of vulcanization) were evaluated. Elastic-strength (conditional tensile strength, elongation at break, hardness) properties of rubber compounds and operational (changes in conditional tensile strength, elongation at break after aging in air) were determined. It was found that the vulcanizing system (3) containing sulfur, peroxide in an amount of 7.0 parts by weight and thiuram accelerator imparts the best elastic and strength properties to rubber compounds and leads to their resistance to high temperatures.


2019 ◽  
Vol 816 ◽  
pp. 192-196
Author(s):  
Alsou D. Nasertdinova ◽  
A.D. Dementev ◽  
A.D. Khusainov ◽  
Svetoslav Isaakovich Volfson

The effect of the type and dosage of sulfur and resin (alkyl phenol formaldehyde resin grade SP - 1045) vulcanizing systems on the oil and petrol resistance and elastic strength properties of thermoplastic vulcanizates (TPV) obtained on the basis of nitrile-butadiene rubber and ABS-plastic, with a ratio of 70/30 respectively has been studied. In the course of studies of vulcanization characteristics, it was found that with an increase in the content of the vulcanizing system, the rate of vulcanization increases both during the vulcanization of rubber compounds and during dynamic vulcanization. The physic-mechanical properties of the TPV obtained indicate that with a fascination for the content of the vulcanizing system, the elastic-strength properties and the oil and petrol resistance of the TPV are also increased.


2013 ◽  
Vol 13 (2) ◽  
pp. 40-43
Author(s):  
Natalia Meissner ◽  
Władysław M. Rzymski

Abstract In this work, composites made from styrene-butadiene rubber and short fibers were prepared by mixing and investigated. The influence on the vulcanization process and tensile strength properties has been studied and compared with compounds filled with carbon black. The presence of fibers gave shorter curing time and led to a slight increase in tensile strength but decreased the elongation at break of the compound.


2021 ◽  
Vol 80 (5) ◽  
pp. 236-240
Author(s):  
С. Кавун ◽  
Н. Королев ◽  
А. Меджибовский

Technological properties of rubber compounds as well as viscous-elastic and strength properties of the tread rubber for heavy-duty tires whole with metal cord (MCT), based on blends of natural (NR) or synthetic polyisoprene of various trade marks (more than 80 %) and polybutadiene (more than 10 %) were studied. The new processing aid (PA), worked out in LLC «NPP QUALITET» under registered trade mark KVALISTROL® A100, was suggested instead of importing analogous of PA Polyplastol 6 type. It was established that replacement of NR in MCT formulation by the SKI-3S rubber produced with the use of a new anti-agglomerator of a crumb of KVANTISLIP® of the BM-2R, PA A100 brand, increased dosage of sulfur-accelerated group and the corrected dosage of the vulcanization inhibiter Santogard PVI and together with the worked out mixing mode at a stage of production of masterbatch allows to receive rubber compound close to reference on the basis of the NR on viscosity. At the same time the new rubber compound's strength and elastic properties practically don't differ, and in the lowered values of a hysteresis, surpass reference rubber compound with NR use.


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