The article investigated the effect of caoutchoucs, sevilen 11808-340, vulcanizing groups, fillers, plasticizers, directional ingredients on the physicomechanical (conditional tensile strength, elongation at break, hardness, rebound elasticity, tear resistance) and operational properties of two rubbers (changes of conditional tensile strength of rubbers after exposure to water, weight changes after aging of rubbers in a solution of citric and hydrochloric acids, changes in the volume of rubbers after exposure to water). These rubbers are developed for the manufacture of the outer and inner layers of water-swelling sealing elements (WSSE) for the oil and gas industry. It has been established that rubber for the outer layer of WSSE based on butadiene-nitrile BNKS-18AMN, isoprene SKI-3 and ethylene-propylene SKEPT-40 caoutchoucs, as well as rubber for the inner layer of WSSE based on butadiene-nitrile BNKS-18AMN, butadiene-methyl styrene SKMS-30AR and ethylene-propylene SKEPT-40 caoutchocs possess the required physical-mechanical and operational properties. It was shown that these rubbers containing a vulcanizing group sulfur + thiazole 2 MBS, sevilen 11808-340, a combination of carbon black T 900 with rosil 175, talc and Karelite MK, petroleum resin “Sibplast”, vermiculite and igloprobivnoe cloth, a combination of hydrosorbtional polyacrylamide 639, sodium polyacrylate, perlite and Kometa-R reagent are characterized by improved physicomechanical and operational properties. These rubbers can be recommended as the basis for the manufacture of the outer and inner layers of water-swellable sealing elements.

Currently, in the oil and gas industry there is a growing demand for sealing elements capable of limited swelling upon contact with water and sealing the annular space of certain sections of the well. The swelling capacity of the sealing elements is predetermined by a well-chosen combination of polymer base and targeted functional ingredients. At the moment, a big drawback of water-swellable sealing elements is the loss of their sealing ability due to the washing out of hydrosorption additives from the sealing element. In this regard, in this work, the effect of hydrosorption polymers (polyacrylamide, sodium carboxymethylcellulose, polyvinyl alcohol and guar gum) on the properties of water-swellable rubber based on a combination of nitrile-butadiene SKN 1855, acrylate nipol AR22 and chloroprene CR 232 rubbers and epoxy 20 with sulfur curing system. The rubber mixture was prepared by mixing rubbers with ingredients on a laboratory roll LB 320 160/160. The rheological characteristics of the rubber compound were studied on an MDR 3000 Basic rheometer at 150 °C. Standard rubber samples were vulcanized at 150 °C for 30 min in a P-V-100-3RT-2-PCD vulcanization press. The main properties of vulcanizates were determined according to the standards in force in the rubber industry. It is shown that the introduction of polyacrylamide together with sodium carboxymethyl cellulose, polyvinyl alcohol and guar gum into a rubber compound leads to a change in its rheological parameters. Vulcanizates containing a combination of polymers are characterized by lower values of the conventional tensile strength and rebound elasticity, but higher elongation at break and the degree of swelling in distilled and formation water as compared to the vulcanizate of the base version of the rubber mixture.

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.

The article investigated the influence of the nature and content of coutchoucs, sevilens, vulcanizing groups, fillers, plasticizers, ingredients of directional action on the technological properties (plasticity, ring modulus, density, start time of vulcanization, stickiness) of two rubber mixtures. These indicators characterize the processability of rubber compounds in the manufacture of products from them. The study was conducted in order to select the basis of rubber compounds for the manufacture of the outer and inner layers of water-swellable sealing elements (WSSE). It has been established that rubber compounds for the outer layer based on butadiene-nitrile BNKS-18AMN, isoprene SKI-3 and ethylene-propylene SKEPT-40 coutchoucs, as well as the inner layer of WSSE based on butadiene-nitrile BNKS-18AMN, butadiene methylstyrene SKMS-30ARK and ethylene-propylene SKEPT-40 rubbers possess satisfactory technological properties. It was shown that these rubber mixtures which contain sevilen 11808-340, a vulcanizing group (sulfur + thiazole 2 MBS + guanid F), a combination of fillers (talc + grew 175 + Karelite MK), petroleum resin Sibplast, directional ingredients (vermiculite + needle punched cloth “Oksipan”), hydrosorption additives (polyacrylamide AK 639 + sodium polyacrylate), have improved technological properties. These rubber mixtures can be recommended as the basis for the manufacture of the outer and inner layers of water-swelling sealing elements for the oil and gas industry.

Silicone rubbers are used for manufacturing fireproof insulating sheaths for cables and high voltage insulators. Highly oil-resistant silicone rubber of brand IRP 1338 of JSC “Kazan plant of synthetic caoutchouc” production should be singled out among silicone rubbers. This rubber is made from synthetic caoutchouc SKTV and contains Aerosil A-300, titanium oxide, fumed silica U-333 curing agent Perkadox BC-FF and anti-structuring agent ND-8 - α,ω-polydimethyl-siloxanediol. Previously we investigated the kinetics of combustion process of this rubber containing anti-structuring agent ND-8 as well as Ca/Zn-stabilizer Kompanoks (2,6-bis((3,5-di-tert-butyl-4-hydroxyphenyl)methyl)cyclohexane-1-one) and their combination which are used to enhance the thermal stability of the rubbers on the basis of carbon-chain caoutchoucs. In given paper using artificial neural networks (ANN) the computational multifactor model of combustion of rubber IRP 1338 has been obtained. The influence of selected stabilizers on the combustion rate of silicone rubber IRP 1338 has been studied. The combustion process was investigated by measuring at different points in time the relative height of the unburned portion of the rubber samples in the form of standard rectangular bars with a size of 10x2x2 mm. Combustion occurred under the action of the infrared beam (wavelength 10.6 μm) of laser LG-25  at three temperatures radiation (800, 900, 1000°C). As the main factors influencing the combustion of rubber, the laser radiation temperature was chosen, under which the forced combustion of rubber occurred. The nature of the stabilizers introduced into the rubber and the combustion temperature of the rubber was measured by a thermocouple placed on the surface of combustion rubber. The objective function of ANN-model was the relative height of the unburned portion of the rubber samples. Moreover, it was believed, the greater the relative height of the unburned portion of the rubber samples, the lower the burning rate and the higher the efficiency of the stabilizer. The received ANN-model has allowed to reveal three stages of combustion of rubber and to investigate features of influence of stabilizers on process of combustion. It was established that from the three stabilizers studied, the Ca/Zn stabilizer most effectively slows down the combustion of rubber due to the interaction of calcium oleates and zinc of this stabilizer with caoutchouc molecules. Thus, the possibility of increasing the fire resistance of rubber based on the silicone rubber SKTV by replacing the anti-structuring agent ND-8 on the Ca/Zn stabilizer has been established.Forcitation:Abrukov V.S., Efimov K.V., Tarasov N.A., Koltsov N.I. Study of influence of stabilizers on burning of silicone rubber with help artificial neural networks. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2018. V. 61. N 1. P. 84-88