Features of spectral analysis of nuclear magnetic resonance signal for express-control of hydrocarbon media

The article substantiates the need to study the structure of the nuclear magnetic resonance signal recorded using the modulation technique. For the stationary and current state, the characteristic features of recording a nuclear magnetic resonance (NMR) signal using the modulation method were determined. The influence of the properties of the medium on the features of recording the NMR signal has been determined. A new method is proposed for determining the contributions of absorption and dispersion signals to the recorded NMR signal. The features of the use of spectral analysis in the study of the NMR signal from hydrocarbon media have been determined.

RESEARCH of ELASTOMERS properties BASED ON COMBINATION OF ISOPRENE AND NITRILE BUTADIENE RUBBERS

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.

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

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

The determination of concentration and components composition for mixtures of hydrocarbon media with its express control

The devices for express control of the state of the environment, based on the phenomenon of nuclear magnetic resonance are described. The new method for liquid mixtures composition determination which did not join each other in a chemical reaction is proposed. Using this methodology allows also to define the relative components concentrations from which the studied mixture was formed. The results of the study of mixtures of hydrocarbon media is presented. The comparison of the calculations of composition and components concentrations for media with experiment is conducted. The Application of the proposed method allows us to determine the contribution of absorption and dispersion signals in registered NMR signal from the condensed medium which is both in a stationary and in a flowing state.

Influence of 6PPD Stabilizer on Climatic Stability of Rubbers Based on Butadiene-Nitrile and Epichlorohydrin Rubbers

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.

Development of Frost-Resistant Rubber Based on Epichlorohydrin Rubber of Hydrin T6000 Brand

The results of development of frost-resistant rubber based on epichlorohydrin rubber (ECHR) of Hydrin T6000 brand of Zeon Chemicals L.P. (USA) are described in the present work. The properties of ECHRs are determined by the nature of the structural units that constitute the macromolecules. The absence of olefinic functionality in the main chain gives ECHR the resistance to heat, oxygen, ozone and other factors. The presence of chlorine causes the high resistance of Hydrin T6000 rubber to the effect of hydrocarbon media (oils, fuels, fats, waxes, solvents), and the presence of oxygen atoms helps to maintain the flexibility and elasticity of materials at low temperatures. Hydrin T6000 rubber has the lowest glass transition temperature (Tgt= -60 ° C) from all the epichlorohydrin rubber brands, high oil resistance, increased heat and ozone resistance, and, therefore, attracts researchers' interest as a promising rubber for the development of frost-resistant rubber with sealing capability. The paper presents the formulation of rubbers based on Hydrin T6000 and the results of studies of their physical and mechanical properties. Analysis of the data revealed that the obtained rubber has excellent frost resistance, increased oil resistance at a satisfactory level of residual deformation after compression and strength characteristics. Thus, Hydrin T6000 has established itself as a promising rubber for manufacturing frost-resistant rubber with sealing function and will provide increased reliability and durability of equipment operation in extreme conditions of cold climate in Russia.