Кераміка: наука і життя

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ISSN / EISSN : 2521-6694 / 2521-6708
Total articles ≅ 111
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O.M. Obodovich, O.M. Nedbailo, O.G. Chernyshyn, A.E. Nedbailo
Кераміка: наука і життя pp 26-29; doi:10.26909/csl.1.2021.4

Abstract:
Acceptance of high-quality aqueous suspensions based on chrysotile asbestos is an urgent technical task in a number of industries. Asbestos-cement mortar is used as an asbestos-cement crust for insulation of walls and other building surfaces, due to this composition of the treated surfaces perfectly retain heat, resistant to moisture, and most importantly - asbestos fibers contribute to the smoothness of the surface and crack is not formed. No less popular is the use of asbestos-cement mortar with a high content of asbestos in the insulation of ventilation ducts and pipelines. This composition of asbestos-cement mortar is used to strengthen the joints of asbestos-cement pipes, as well as as a filler in the laying of cast iron pipes to give the joints additional elasticity. Asbestos-cement mortar has plasticity, resistance to stretching and reinforcement of asbestos, as well as strength and versatility in the use of cement. Due to these properties, asbestos and cement perfectly adhere to each other to obtain a durable, strong, frost-resistant, virtually waterproof and fire-resistant building material. The result of the microscopic examination is reason to believe that from the technological process of production of slate can be removed electromechanical mixer for the preparation of a solution of asbestos + water + portland cement. In this case, given the fact of continued loosening of asbestos in the preparation of the mold mixture of asbestos + water + portland cement, it will be sufficient to ensure the degree of loosening of asbestos in the ripper at the minimum required level (for example, not more than 85%). It is assumed to obtain a mold mixture with a high degree of homogeneity of the components with reduced costs of Portland cement due to its physico-chemical activation by hydraulic fluxes.
Кераміка: наука і життя pp 7-13; doi:10.26909/csl.1.2021.1

Abstract:
The aim of this work was to find the optimal conditions for the formation of nanocomposites, study their structure and properties and conditions for the formation of multicomponent materials based on epoxy polymers and carbon nanotubes with predetermined performance properties. The basis for the formation of epoxy polymers was an epoxydian oligomer (EDO) based on bisphenol A. Polypox H354 was used as a hardener for EDO. Carbon nanotubes (CNT) were used as a nanofiller for the preparation of nanocomposites. The research methods were a diffractometer for measuring the intensity of X-ray scattering in the region of small angles and a differential scanning calorimeter for obtaining heating thermograms. The electrical conductivity of the samples at a temperature of 293 K was measured at direct current according to the two-electrode scheme. In this work the structure, thermophysical properties and electrical conductivity of nanocomposites based epoxy polymers and carbon nanotubes have been studied. It was found that at low CNT content the formation of nanocomposites occurs by the mechanism of epoxy network growth, which is accompanied by the displacement of CNT particles to the periphery of the epoxy matrix. This process is accompanied by an increase in the scattering intensity of the SAXS, a rapid increase in the glass transition temperature and the degree of crosslinking of the epoxy polymer. When the critical concentration is reached, CNT particles form a continuous cluster, which leads to occurrence percolation threshold, reducing the glass transition temperature, expanding the glass transition range, occurrence of pores and reducing the degree of completion of the crosslinking reaction in nanocomposites relative to the epoxy polymer. It is established that the improvement of nanocomposite properties and the occurrence of the percolation threshold is due to the maximum specific energy of ER-CNT interaction and is achieved at a critical mass concentration of nanofiller from 0,1% to 0,4%.
, , O.I. Fesenko, Yu.O. Smirnova, E. Bairamov
Кераміка: наука і життя pp 19-25; doi:10.26909/csl.1.2021.3

Abstract:
The need to improve the level of dental health of the population of Ukraine was identified. The prospects for the use of ceramic prostheses to provide quality medical care in dentistry have been established. An analytical review of various types of ceramic and glass-ceramic materials used as dental prostheses for tooth replacement: porcelain, alumina, zirconium oxide, glass-ceramics based on leucite and lithium disilicate and mica with the addition of fluorides. Peculiarities of the structure and operational properties of ceramic and glass-ceramic materials for dentistry have been identified, their advantages and disadvantages have been established. The effectiveness of the use of glass-ceramic materials based on lithium disilicate for dental prosthetics is substantiated. The basic lithium silicate system was selected and glasses for obtaining glass-ceramic crowns based on lithium disilicate by the method of high-temperature pressing and calcium phosphate-silicate system for obtaining glass-ceramic coatings were synthesized. The methodological approach to the development of glass-ceramic prostheses based on lithium disilicate is determined. The limits of the compositions of oxide components are determined and raw materials for the synthesis of the glass matrix are selected. The technological parameters of melting (T = 1350 – 1400ºС) and heat treatment with simultaneous formation of products (stage of nucleation T = 600 – 650ºС, τ = 30 – 60 min; stages of formation T = 900ºС, τ ≈ 20 min) are selected. The composition of fluoroapatite glass-ceramic coating for glazing of glass-ceramics and the mode of its firing (T = 800 – 850ºС, τ ≈ 1,0 – 1,5 min) were determined. The serviceability of the developed glass-ceramic samples DL st.glass, which were obtained by the technology of high-temperature pressing, are determined. The comparative analysis of glass-ceramic prostheses for dentistry allowed to establish that the operational properties of the developed glass-ceramic prostheses according to ISO 6872:2015 are at the level of world analogues. This will allow them to successfully compete in the Ukrainian market with well-known foreign counterparts and help ensure the social priorities of the state in the field of health care.
Zh.O. Petrova, Yu.P. Novikova
Кераміка: наука і життя pp 14-18; doi:10.26909/csl.1.2021.2

Abstract:
The article presents research on the preparation of raw materials, creation and granulation of compositions from obsolete sludge deposits of peat and biomass. Studies of raw material preparation processes have shown that obsolete sludge deposits have excessive ash content. To reduce ash content, it is advisable to add peat and biomass to sludge. During the study of peat, it was determined that peat extracted from the floodplain of Irpen has a high ash content, so for further research used peat from Chernihiv. The created compositions were subjected to granulation in different compositions and ratios. Preliminary dehydration of peat in the drying cabinet and moistening of the sludge were performed to create different sludge-peat mixtures with different moisture content of sludge and peat. When creating two-component compositions to sludge-peat add biomass. Studies have allowed us to choose the optimal ratio for granulation.
D.M. Korinchuk
Кераміка: наука і життя pp 13-16; doi:10.26909/csl.4.2020.2

Abstract:
With modern world trends in the growth of consumption of products of various industries and the environmental situation, the problem of rational use of energy and raw materials in industrial production in order to obtain the maximum amount of finished product of a given quality. An important step in solving this problem is to create an adequate mathematical model of the process. A simplified model of the process of dehydration of the aqueous solution film on the surface of a single granule in the production of multilayer composites in a granulator dryer has been developed. Simulation of pellet dehydration includes analysis of heat distribution in a spherical material and in a film of liquid (heat exchange) covering the sphere, and the process of evaporation of the mixture film (mass transfer), which take place simultaneously. The results can be applied at the stages of design and testing of the granulator.
S.M. Ponomarenko
Кераміка: наука і життя pp 17-22; doi:10.26909/csl.4.2020.3

Abstract:
The problem that arises during the operation of tires is cyclic deformation, in which there is a conversion of mechanical energy into heat. However, due to the low thermal conductivity of rubber, repeated cyclic loads of products based on them lead to heating, which is due to the phenomenon of mechanical hysteresis. The consequence is a deterioration of their performance over time and, as a consequence, a reduction in service life. The main method for increasing the interfacial interaction for ceramic fillers is to ensure the penetration of rubber molecules into the interplanar space (gallery) formed by the filler particles (intercalation), and the subsequent distribution of these nanoplates (exfoliation) to a thickness of several nanometers throughout the field. The aim of this work is to study the thermoelastic properties of rubbers made on the basis of nanosized mineral filler montmorillonite, which may indicate a way to solve the problem of their durability. It was investigate the influence of modified nanosize montmorilonit on thermoelastic properties of rubber composites on it basis. It is rotined that thermoelastic properties described a model, which takes into account holdings of local increase of tension for a rubber matrix and destruction of spatial net of nanoparticles with the increase of strein, which results in exotherms which show up as a result of friction between the filler particles. Quantitative analysis of the thermoelastic properties of rubber nanocomposites provides additional confirmation of the concept of the reinforcement factor, which depends on the deformation, and determines the thermoelastic properties of nanocomposites for the whole range of relative elongations.
O.M. Nedbailo, O.G. Chernyshyn
Кераміка: наука і життя pp 7-12; doi:10.26909/csl.4.2020.1

Abstract:
The article summarizes and analyzes the technological characteristics of various clay raw materials. Recommendations on the feasibility of their use in various types of ceramic production are given. Their main characteristics are given, such as chemical composition, mineralogical and physical properties, which vary within extremely wide limits. They are most characterized by a layered structure. All clay minerals are considered as secondary geological formations that arose in deposits in which water was present as a product of changes in aluminosilicate rocks. Most clay minerals are the product of weathering and deposition, but they can also be formed in hydrothermal conditions. In addition to basic clay minerals, clays also contain various amounts of other minerals that often affect their behavior when used. The most common such minerals are quartz, feldspar and minerals containing iron, lime, alkalis and soluble salts. The organic component is also found in many clay deposits. Different classifications of clays are based on their geology, mineralogy, composition, properties and uses, but none of them covers all possible diversity.
O.M. Nedbailo, O.G. Chernyshyn
Кераміка: наука і життя pp 23-28; doi:10.26909/csl.3.2020.4

Abstract:
Some aspects of resource saving problem in the process of construction of heated construction installations are considered in the paper, also heat transfer problem in porouse concrete. Is paid attention to necessity of application with mass construction of habitation of products from porouse concrete, first of all - products from of cellular concrete. In article the basic requirements of the standard documents regulating constructive properties of various building materials, including various concrete are analysed. The design a warm wall on the basis of products from porous concrete is considered. Its advantages in comparison with known designs of warm walls are shown. In article changes of technological properties of various building materials are considered at influence on them of a moisture. The analysis of the standard-regulating documents, concerning operational qualities, concerning reliability and durability of designs is carried out. The basic technical properties gas-concrete non-autoclave solidification on the basis of a waste stone machining are analysed. Results of researches technology indicators cement cellular concrete non-autoclave solidification with offered filling material are resulted.
L.I. Melnyk, , O.V. Kozlovets
Кераміка: наука і життя pp 13-17; doi:10.26909/csl.3.2020.2

Abstract:
Composite materials for various purposes are made on the basis of initial mixtures of fillers and bonding components. The varieties of these components and their quantitative ratio determine the qualitative indicators of the composite. This causes rosettes of the raw material base for the production of composites, including the use of by-products of mineral extraction, which meets the objectives of resource saving. This paper presents the results of the study of composite materials on the basis of by-products of extraction of igneous rocks of Transcarpathia - siftings of andesite as a filler and copolymer Latex 2012 as a matrix. The analysis of chemical and mineralogical composition of andesite siftings from Khust quarry was carried out. An analysis of the dependence of the main physical and mechanical characteristics of the studied composites on the concentration of andesite in the range of 55-85 wt. % and of the corresponding change in the quantitative ratio of filler and copolymer is performed. Differences in parameters using andesite samples with different particle size distribution (the poly-fractional with particle size ˂ 3 mm and the dispersion one with particle size ˂ 0.5 mm) were determined. The peculiarities of the formation of the pore structure of the composite material obtained using andesite samples of different granulometry connected with the increasing degree of dispersion associated with the increase in the number of filler particles in the composite, increasing adhesion forces in the copolymer-filler system and increasing of surface energy of andesite particles are shown. The possibility of increasing the abrasive resistance of the composite material when using the initial mixture based on the andesite-copolymer system has been experimentally confirmed.
Yu.F. Snezhkin, V.м. Paziuk, Zh.O. Petrova
Кераміка: наука і життя pp 7-12; doi:10.26909/csl.3.2020.1

Abstract:
Heat pump technologies have become widely used in space heating and air conditioning systems, and the heat pump can be used for low-temperature drying of capillary-porous materials. Recuperative and condensing heat pumps, which allow both drying and cooling of the material, have become the most widespread. The developed condensing heat pump drying unit with a mine chamber implements a low-temperature drying process of spherical capillary-porous materials at a drying agent temperature of 40-50°C with a decrease in material humidity by 11% to a final humidity of 8%. Experimental studies on a heat pump drying unit for drying capillary-porous materials of spherical shape indicated a significant reduction in average energy costs per process up to 3700 - 4100 kJ/kg of evaporated moisture. The increase in energy consumption increases significantly in the second part of the second period, where heat consumption can reach 5000 - 5350 kJ/kg of evaporated moisture. The use of condensing heat pumps for low-temperature drying of capillary-porous materials has shown high energy efficiency compared to existing drying technologies.
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