Elastomeric Composition Research Articles

Ecological and Technological Aspects of Liquid-phase Filling of Styrene-butadiene Rubber with Black Carbon in an Ultrasonic Field

It has been found that black carbon exhibits increased sorption activity in relation to the emulsifying agents of the latex system under ultrasonic impact, which contributes to destabilization of the latex and the release of the elastomeric composition without the use of coagulating agents. It was revealed that as a result of the black carbon sorption of non-biodegradable leukanol, emulsifying substances in the form of resin soaps and fatty acids, the overall pollution of wastewater is reduced, and treatment efficiency of up to 98% is achieved in terms of COD. It has been shown that the liquid-phase filling of SKS-30ARK rubber at the latex stage with high-structural black carbon of grade P245 at a ratio, wt. part — rubber: black carbon = 100 : 100 allows to reduce the content of non-biodegradable leukanol down to 0.1 mg/dm3 and increase the biooxidability index of wastewater to 83%.

Formation of Elastomeric Composition Properties in the Presence of Bioingredient

Peculiarities of formation of technological, vulcanization, dynamic, relaxation, and physicomechanical properties of elastomeric composition used for the tread production have been studied in the presence of bioingredient as a plasticizer-softener. Bioingredient is an organic component of sunflower oil winterization by-product (OSSO product). It was found that the OSSO product increases the cohesive strength of the rubber compound by 1.5 times in comparison with the industrial petrochemical lubricants. Under the same vulcanization conditions, the bioingredient provides 30–40 % higher resistance to reversion and relaxation processes at 373 K, lower dynamic losses, as well a high level of physical and mechanical characteristics.

Evaluation of the possibility of using regenerating oil and fat industry waste in elastomeric compound

The paper reports the way of regenerating the oil and fat industry waste by using in elastomeric composition based on polydiene. Chemical composition, physical and mechanical properties of oil- and wax-containing fraction as a secondary raw material of sunflower oil production were determined using modern instrumental methods. The complex of technological, vulcanization, physical, mechanical, and other properties of filled and non-filled model elastomeric composition based on butadiene--methylstyrene rubber with 1.5 phr of oil- and wax-containing fraction was studied. The feasibility of using the studied bio-additives in filled elastomeric compositions with provides a high level of their properties and widens the range of ecologically safe ingredients from renewable plant raw material.

Study of the influence of temperature-time conditions of vulcanization on the properties of elastomer compositions

The article was devoted to the study of the influence of temperature-time conditions of vulcanization on the kinetic parameters of structuring of rubber compounds and the physical and mechanical properties of rubbers. The object of the study was an elastomeric composition based on natural rubber and containing a sulfur curing system. The investigated rubbers were obtained under various time conditions and temperatures of 143, 160 and 170°C. It was determined that with an increase in the vulcanization temperature, the values ​​of the minimum torque decrease by 11.6–15.6%, and the maximum torque increase by 3.5–4.1%, at the same time the density of rubber cross-linking increases by 6.2– 7.5%. Analysis of the results of determining the physical and mechanical parameters of rubbers revealed that at a temperature of 143°C the vulcanization time does not significantly affect the elastic-strength parameters of rubbers and vulcanizates are characterized by the highest values of tensile strength both before and after thermal aging. It has been established that with an increase in the vulcanization temperature, side processes are activated, leading to a decrease in the elastic-strength properties of rubber (a decrease in tensile strength by 9.2–16.4% and elongation at break up to 7.2%). Vulcanizates obtained at 170°C are characterized by the lowest indicators of elastic-strength properties, hardness Shore A and rebound resilience, which is due to the density of the network and the nature of cross-links. The research results showed that when choosing the final vulcanization mode, especially for multilayer products, it is necessary to take into account not only the energy consumption in the production of finished products, but also the influence of temperature and time parameters on the complex of physical and mechanical properties of each component of the product.

ELASTOMERIC COMPOSITIONS WITH A HIGH CONTENT OF CHRYSOTILE ASBESTOS

The studies have shown the possibility of increasing the safety level of chrysotile asbestos (AX) in the technological process of its use in elastomeric compositions. This is achieved by dispersing ACh in a lactam-containing melt. As a result, dispersed ACh almost completely eliminates dusting, which is the main essence of increasing its safety level and allows solving the problem of its maximum content in elastomeric compositions, which in turn provides the necessary level of swelling of the elastomeric composition as a whole upon its contact with working fluids. drilling wells.

ELASTOMERS WITH A HIGH CONTENT OF MODIFIED CARBOXYMETHYLCELLULOSE

The use of lactam-containing complex salts (LCS) with the functions of dispersants, apparatuses and crosslinking agents made it possible to obtain elastomers with a high (at least 300 wt.% per 100 wt.h. of rubber), containing modified carboxymethyl cellulose for the cuff of a packer device capable of performing the necessary shut-off functions in contact with highly concentrated, at least 25% aqueous solutions of mineral salts - NaCl and CaCl2. The achieved effect is expressed in the ability of LCS to disperse water-swelling polymers (GNP), to have an appreting effect on GNP particles, thereby preventing their agglomeration, as well as to create additional chemisorption bonds in the rubber matrix. As a result, a developed network of interface boundaries is obtained, which contributes to the rapid penetration of aqueous solutions of mineral salts into the array of elastomeric composition.

Development of high melt strength polypropylene and its application in thermoplastic elastomeric composition

High melt strength polypropylene (HMS-PP) with a long-chain branched structure is a modified form of polypropylene (PP) which has basic properties of regular PP but with superior melt drawability. This paper reports on the development of gel-free HMS-PP from a linear isotactic PP through the introduction of long-chain branching on its backbone via a reactive extrusion process, using dicetyl-peroxydicarbonate (PODIC) alone or in combination with a coagent. The melt strength and the mechanical properties such as impact and flexural strength of PP showed improvements with the modification with PODIC. 5000 ppm by weight of PODIC was found to provide the best balance of properties. The efficacies of zinc diethyldithiocarbamate (ZDC) and tetramethyl thiuram disulphide (TMTD) as coagents in combination with PODIC to augment properties of HMS-PP further were explored. TMTD offered slightly enhanced performance benefits as compared to ZDC at an optimized concentration of 100 ppm by weight. The application potential of HMS-PP in thermoplastic elastomeric blends of HMS-PP with ethylene-propylene-diene monomer (EPDM) rubber at a fixed ratio of 35/65 by weight was also investigated. Structure-property correlations were established between the extent of long-chain branching in the modified PP and the properties of the resultant thermoplastic elastomeric composition.

Effect of Ground Vulcanizate Modification Methods on Properties of Oil-Petroleum-Resistant Rubber

In this paper, the influence of the modification method applied to ground vulcanizate (GV) on the properties of elastomeric compositions based on nitrile rubber is discussed. Modified GV has been mixed with the elastomeric composition, which is used for the manufacturing of oil-petroleum-resistant rubber products.The work takes into consideration two types of GV with different chemical nature. The first GV type is rubber crumb produced from end-of-life tires. The second GV type was obtained from rubber wastes based on nitrile rubber. Three methods of the modification are compared in the research: mechanical activation in a planetary ball mill, swelling in a Polyethylene glycol (PEG-400) medium, and the mechano-chemical transformation of GV with PEG-4000. It is shown that depending on the dosage addition of GV modified with PEG-4000 reduce the compression set up for (16.1±0.7%), the strength decreases only by 2.1–8.3%, and the elongation at break increases by 0.8–10.3% compared to rubber without additives.

Elastomeric composition for intrinsically stretchable organic light emitting diodes

Elastomeric composition for intrinsically stretchable organic light emitting diodes

Fluoroelastomers reinforced with carbon nanofibers: A survey on rheological, swelling, mechanical, morphological, and prediction of the thermal degradation kinetic behavior

Fluoroelastomer (FE) reinforced with carbon nanofiber (CNF) (1 and 2 phr) was prepared using an instrumented batch mixer. A property–structure relationship was compared with the compounds containing carbon black (30 phr), neat FE, and hybrid sample (nanofiber + carbon black, 2 phr + 30 phr, respectively). Nanofiber did not improve the mechanical behavior while swelling characteristic was improved as well the initial weight loss by thermogravimetry. The compounds achieve conductive characteristic using only 1 phr. The thermal decomposition of the compounds was carried out using different kinetic approaches in order to establish consistent parameters. It has been shown that the approaches using consistent kinetic parameters can be combined in such a way as to enhance the reliability and quality of each other and consequently the overall kinetic analysis. The limited dispersion with agglomerations seems to be the crucial factor for all analyses evaluated. Finally, the synergism between nanofiber and carbon black for hybrid compound make CNFs very attractive to be used as an additive in the elastomeric composition. POLYM. ENG. SCI., 59:1223–1232 2019. © 2019 Society of Plastics Engineers

Properties of Elastomeric Adhesive Composition Based on Chlorinated Isobutylene Isoprene Rubber Obtained by Mechanochemical Halide Modification

This paper is devoted to the main characteristics of adhesive composites based on chlorinated isobutylene isoprene rubber with different content of chlorine obtained by the novel technology of mechanochemical halide modification of rubbers based on mechanical initiating of the combination reaction of halide in liquid phase. In the work the basic properties characterizing adhesive, protective and paint coatings have been studied with the main focus on dependence of the materials properties on chlorine content in chlorinated isobutylene isoprene rubber used as polymer basis of adhesive compositions under investigation. Based on the study results of the technological properties of elastomeric adhesive composition, the optimal adhesive composition has been recommended.

Properties of elastomeric composition filled with ground vulcanizate

Recycling rubber waste and improving of the efficiency of the secondary elastomeric materials use is an important technical and economic challenge. Vulcanized rubber waste is the most difficult to recycle. One of the promising ways of recycling waste vulcanized rubber is their grinding and subsequent use of the obtained powder as a filler in elastomeric compositions. The influence of the nature of ground vulcanizate (GV) on the properties of elastomeric compositions based on nitrile-butadiene rubber is studied in the paper. GV of two types are used for the investigation. The first type is tire based on non-polar rubbers of general purpose. The second type is obtained from wastes of production of industrial rubber article (IRA) based on polar nitrile-butadiene rubber. Particle size of GV’s fraction used in study is 0.63–1.00 mm. GV was input in unfilled model composition based on nitrile-butadiene rubber in dosages 50, 100, 150 and 200 phr. It is found that Mooney viscosity of the elastomeric compositions filled with GV of IRA wastes increases more than using the tire GV. The rate of stress relaxation in the uncured compositions are not depend on the nature of GV. The cure optimum of the composition containing GV-based on polar rubber smaller than GV based on general purpose rubbers is used. The influence of the ground rubber type and dosage on the cure network structure are investigated. the density of cross-linking of the vulcanizates decreases with increasing dosage GV. Vulcanizates filled with GV derived from IRA have higher cross-linking density than those containing tire GV.

The influence of adhesion promoters on elastic and strength properties and structure of elastomeric compositions

The effect of new promoters on the adhesion of elastic and strength properties unfilled elastomeric compositions based on synthetic isoprene rubber SKI-3 and also on the structure of their vulcanizates are investigated. Synthesized adhesion promoters constitute silica fillers modified with cobalt, nickel, and a combination of cobalt and nickel. They contain on the surface a reduced number (compared with industrial stearate, cobalt) ions of metals of variable valence. Tests are carried out to determine the dependency of changes of the tensile strength, the elongation at break and the density of the crosslinking of rubbers on dosages of the investigated adhesion promoters and amounts of metal ions on their surface. The effect of type and dosage of the synthesized promoters of adhesion of rubber to steel brassedcord on heat aging resistance of elastomeric compositions are established. It is established that the vulcanizates containing synthesized adhesion promoters have greater high temperatures resistance as compared with the rubber materials containing industrial cobalt stearate. Increasing dosages of modified silica acid fillers in elastomeric compositions, quantity of metals on their surface leads to the decrease of the resistance of vulcanizates to heat ageing. While Nickel ions have less oxidation effect on rubber, compared to cobalt ions that may be due to their lesser activity It is determined that the introduction of adhesion promoters leads to the formation of additional cross-linking. It is revealed that use the mineral promoters in the elastomeric compositions affects less the density of cross-linkage of rubber after heat aging as compared with the cobalt stearate. When administered in an elastomeric composition the silica modified nickel, increasing the crosslinking density of rubber upon exposure to elevated temperatures was observed.

Influence of dispersants on aging and frost elastomeric compositions based on butadiene acrylonitrile rubbers

The possibility of use of dispergators of various nature for production of rubber technical products with expanded temperature conditions of operation is studied. It is investigated influences of dispergators of Dispergator FL and INT 159 on properties of rubber mixes for receiving products with high resistance to thermal aging or frost resistance. Research of influence of modifiers was conducted for rubber mixes on the basis of butadienenitrile rubbers synthetic (BNRS)-18 and BNRS-28. I’s established that at addition of a dispergator of Dispergator FL the indicator of relative deformatstion of compression (RDC) and respectively heat stability of rubbers increases. Introduction to structure of elastomeric composition of a dispergator of INT 159 practically doesn’t influence frost resistance, and Dispergator FL worsens her (the coefficient of frost resistance decreases by 15.4–17.8%). Possibly it is connected with the fact that at the lowered temperatures in the presence of Dispergator FL there is a bigger delay of relaxation processes and decrease in energy of the thermal movement of links of macromolecules of rubbers. It becomes insufficient for overcoming of intermolecular interaction in the modified system and commission of conformational transitions of macromolecules under the influence of external loading. Mechanical energy is to a large extent mentioned not on change of a form of macromolecules, and on their mechanodestruction. However, it increases heat stability since it that is higher, than molecular mobility is lower. INT 159 dispergator components, settling down on borders of supramolecular formations of elastomers, increase mobility of links of macromolecules of rubbers, weaken chemical bonds in them, reduce thermal stability, but at the same time INT 159 dispergator practically doesn’t reduce frost resistance therefore it is expedient to apply it when receiving frost-resistant elastomeric composition. Thus, when receiving thermostable elastomeric compositions it is necessary to use Dispergator FL, and frost-resistant – INT 159 dispergator.

Degradation of different elastomeric polymers in simulated geothermal environments at 300 °C

This study evaluates the degradation of six different elastomeric polymers used for O-rings: EPDM, FEPM, type I- and II-FKM, FFKM, and FSR, in five different simulated geothermal environments at 300 °C: 1) non-aerated steam/cooling cycles, 2) aerated steam/cooling cycles, 3) water-based drilling fluid, 4) CO2-rich geo-brine fluid, and, 5) heat–cool water quenching cycles. The factors assessed included the extent of oxidation, changes in thermal behavior, micro-defects, permeation of ionic species from the test environments into the O-rings, silicate-related scale-deposition, and changes in the O-rings' elastic modulus.The reliability of the O-rings to maintain their integrity depended on the elastomeric polymer composition and the exposure environment. FSR disintegrated while EPDM was oxidized only to some degree in all the environments, FKM withstood heat-water quenching but underwent chemical degradation, FEPM survived in all the environments with the exception of heat-water quenching where it underwent severe oxidation-induced degradation, and FFKM displayed outstanding compatibility with all the tested environments. This paper discusses the degradation mechanisms of the polymers under the aforementioned conditions.

Behaviour of Elastomeric Composition With High-Disperse Carbon Additives at Various Steps of the Process

Behaviour of Elastomeric Composition With High-Disperse Carbon Additives at Various Steps of the Process

Thermoplastic elastomeric composition based on maleic anhydride–grafted ground rubber tire

Thermoplastic elastomeric composition based on maleic anhydride–grafted ground rubber tire

Thermoplastic elastomeric composition based on maleic anhydride–grafted ground rubber tire

AbstractGround rubber tire (GRT) powder was maleated in an internal mixer using maleic anhydride and dicumyl peroxide at 160°C. Maleated GRT was characterized by using X‐ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, wettability, and differential scanning calorimetry. The physical properties of the dynamically vulcanized 60 : 40, rubber : plastic composition based on acrylated high‐density polyethylene as the plastic phase and ethylene propylene diene rubber containing maleated GRT as the rubber phase were found to be greater than the corresponding composition containing nonmaleated GRT. The blend was found to be reprocessable, like themoplastic elastomers. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 370–378, 2002; DOI 10.1002/app.10348

Recycling of EPDM waste. II. Replacement of virgin rubber by ground EPDM vulcanizate in EPDM/PP thermoplastic elastomeric composition

Recycling of EPDM waste. II. Replacement of virgin rubber by ground EPDM vulcanizate in EPDM/PP thermoplastic elastomeric composition

Recycling of EPDM waste. II. Replacement of virgin rubber by ground EPDM vulcanizate in EPDM/PP thermoplastic elastomeric composition

AbstractVirgin ethylene propylene diene monomer (EPDM) rubber in a thermoplastic elastomeric blend of polypropylene (PP) and EPDM rubber was substituted by ground EPDM vulcanizate of known composition, after which the mechanical properties of the raw EPDM/waste EPDM/PP blends were determined. The ratio of the rubber content in the waste EPDM (r‐W‐EPDM) to the raw EPDM (R‐EPDM) in the blends was varied from 0 : 100 to 45 : 55. Attempts to replace higher amounts (>45%) of R‐EPDM by W‐EPDM failed because of processing difficulty. Although a drop in mechanical properties of the blends was observed at lower loadings of W‐EPDM, the properties showed improvement at intermediate W‐EPDM loadings. The R‐EPDM/W–EPDM/PP blends were found to be reprocessable. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 3304–3312, 2001