Nanotechnologies in Construction: A Scientific Internet-Journal @nanobuild-en
Статьи журнала - Nanotechnologies in Construction: A Scientific Internet-Journal
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Nanostructured foam ceramics for building purposes: production technology and applications
Статья научная
Introduction. Foam-ceramic heat-insulating building materials have the greatest stability of the demanded technological characteristics due to their unique physical and technical properties. Increasing the large-capacity production of nanostructured foam-ceramic products and developing educational programs for advanced training of process engineers remains an urgent task. Methods and materials. A technological method for manufacturing nanostructured foam ceramics is the method of direct foaming: ceramic foams are created by involving atmospheric air in a suspension. Further, the consolidated foams are carefully dried and sintered for 12 hours by heat treatment (950–1100оC) to obtain sufficiently high-strength foam ceramics for building purposes. The most important raw materials for the production of construction foam ceramics are clays, diatomites, siliceous minerals, zeolite rocks, etc., as well as ceramic and slag waste, and the like. Results. The technology of production of foam-ceramic materials for building purposes based on clay raw materials has been developed. As a result of physical and chemical transformations in the production cycle, including firing, uniformly closed micropores of foam ceramics with a diameter of up to 120 microns are formed, and the wall thickness varies from 1.8 microns to 6.3 microns. The compressive strength of the obtained nanostructured construction foam-ceramic products with an average density of 450–850 kg/m3 is 3–8 MPa, thermal conductivity is 0.12–0.15 W / (m●оC), frost resistance is at least 50 cycles. Discussion. In large-scale technological production, bubbles mass (three-phase foam) can be obtained by mixing nanostructured foam with a highly dispersed mineral powder. By controlled sintering, a dried foam mass is produced with the required technological characteristics due to the crystal bond of a solid-phase mullite based on cluster microparticles with dimensions of 15–200 nm, and the walls of micropores and nodal joints of nanostructured foam ceramics provide high mechanical strength, hydrophobicity and chemical resistance. Conclusions. Nanostructured foam ceramics for building purposes is sufficiently moisture-resistant, since it has a microstructure of closed ultramicropores; it is resistant to chemical and physical effects and therefore is the optimal thermal insulation material.
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Статья научная
Introduction. Currently, the development of photocatalytically active cement-based materials with self-cleaning properties is a promising area of building materials science. Self-cleaning concrete is obtained by using photocatalytic additives, of which titanium dioxide (TiO2) is the most common. It has been found that the functional properties of TiO2 depend largely on its phase composition. This study aimed to establish the patterns of influence of phase composition on the photocatalytic activity of titanium dioxide under the impact of artificial ultraviolet and natural solar radiation and to identify the most effective titanium oxide-based photocatalysts for subsequent use in the composition of self-cleaning concrete. Methods and materials. Four titanium dioxide samples, namely two industrial samples and two samples synthesized by hydrolysis of titanium alkoxide in acidified water-alcoholic medium followed by calcination at 500 °C, were the objects of the study. X-ray powder diffractometry was the method used to investigate the structure parameters of TiO2 samples. The model reaction of oxidative degradation of methylene blue under UV- and daylight exposure was the means for studying the photocatalytic activity of titanium dioxide samples. Results and discussion. It was found that polymorphic modifications of titanium dioxide had a multidirectional effect on its functional characteristics, in particular, a rise in the content of anatase and rutile led to an increase and decrease in the photoactivity of TiO2 samples, respectively. The single-phase sample with anatase structure was most effective under UV irradiation, while the three-phase sample with the anatase : brookite : rutile ratio of 67% : 13% : 20% had the highest activity under daylight exposure. The photocatalyst composition, including several polymorphs of TiO2 with a predominance of anatase form (more than 50%), allowed to achieve a synergistic effect of increasing the photocatalytic activity of titanium dioxide under conditions of solar radiation due to the formation of type-II semiconductor heterojunctions. Heterostructures made it possible to improve the spatial separation of charge carriers and to reduce the recombination rate of photogenerated electron-hole pairs. Conclusion. The obtained results indicated the possibility of improving the functional characteristics of titanium oxide-based additives for self-cleaning concrete due to the targeted regulation of their phase composition by optimizing the synthesis parameters of photocatalytic modifiers.
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Статья научная
Introduction. The aim of the study was to optimize the quality control of fire retardant coatings (FRC) during their production and use. The results of a comparative analysis of the consequences of fires and their causes with the parameter of fire resistance of objects indicate that the number of fires and damage from them in buildings of the first degree of fire resistance is almost an order of magnitude smaller than in buildings of the second degree of fire resistance. Consequently, increasing the fire resistance of building materials and structures is the way to radically reduce fires and losses from them. Methods and materials. Based on a system analysis of existing fire protection technologies for building materials made of wood, metals, rubber and polymers, nanotechnologies were developed to determine the stability of samples with an FRC on the baro-electro-thermo-acoustic (BETA) analyzer and create their «images» for further diagnosis of their aging at the constructions and operation facility. The novelty of the study is protected by patents of the Russian Federation. Results and discussion. The obtained results consist in the refinement of computational algorithms for the FRC in the BETA analyzer, as well as in the development of a portable automated complex, which allows to determine the stage of «aging» of the FRC on these materials, and, consequently, their durability and update time. This conclusion is based, firstly, on the results of the development of a thermo-electro-dilatometer crucible for controlling liquid and viscous materials by the authors of the «float design», which will make it possible to control the FRC characteristics during their production, and secondly, to carry out express control after filling them in containers (polymer, metal, glass) without opening it and thirdly, due to the recognition of these «images» using thermo-electro-measurements of the FRC using special probes connected to a portable automated system. Conclusion. The results obtained make it possible to «arm» with portable automated systems not only construction and fire control authorities, but also manufacturers of emergency protection products. This will allow, according to the authors, to fundamentally solve the problems of quality and durability of FRC, but the main thing is to guarantee the stability of the protected materials and structures from them.
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Статья научная
Introduction. To determine the effectiveness of fire-retardant coatings (FRC), a system of methods for fire and high-temperature testing of fire-retardant materials and structures made of themis being used. However, there are no methods and means that could provide current effectiveness of fire protection, and existing methods cannot be applied to determine fire resistance of building structures with fire protection, they set only a group of the effectiveness of the flame retardants. Therefore, to assess the quality and durability of the FRC, in case they provide the parameters of thermal stability of the protected materials, structures and elements of the engineering systems of the objects, it was necessary to develop a quickmethod and a portable diagnostic complex of fire-retardant coatings (PDC FRC). Methods, models and tools. Based on a system analysis of the existing fire protection technologies for building materials from wood, metals, rubber and polymers, a rapid analysis methodology and PDC for thermo-electro-acoustic (TEA) sensing of FRCs using thermo-acoustic methods have been developed. That made it possible to determine thermal conductivity, the ultrasound speed and its absorption coefficient in the FRC, as well as to conduct a comparative analysis of the «FRC image» obtained on a BETA-analyzer with measured characteristics, based on which to calculate the time of its operability. Results and discussion. The PDC of FRC consists of a case with a laptop, with the immitance meter and a two-channel oscillographic attachment connected to the laptop, to the inputs of which a TEA-zonding unit is pressed, pressed to the FRC of the tested object (structure, material, cable), by thermal, electrical and acoustic signals from which the laptop software identifies the properties and stages of operational stability of the FRC. The PDC of the FRC and the proposed approach allowed us to synthesize a model of the Internet system of TEA - diagnosis of FRC and of the monitoring of the operational stability of the protected materials. The novelty of the study is protected by patents of the Russian Federation. Conclusion. The proposed approach and the PDC of the FRC made it possible to implement a quickanalysis of the FRC at the facility and to synthesize a model of the Internet system of TEA-diagnostics of FRC, which can become the basis of the national supervision system for the given area.
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Nanotechnologies: a review of inventions and utility models. Part I
Статья научная
A brief review of patents is given. The research performed by scientists, engineers and specialists in the area of nanotechnologies and nanomaterials resulted in increased efficiency of construction, housing sector and adjacent fields of economy. For example, the invention «А method to produce titanium carbide nanopowder» refers to inorganic chemistry and nanotechnology and can be used to produce wear-resistant abrasive materials, high-temperature ceramic materials and coatings, high-strength composite materials. The technical result is TiC nanopowder in free-filled condition in the form of particles with average size no less than 30 nm, as well as TiC nanopowder with controlled ratio titanium-carbon. All that boosts technical opportunities for its application. The specialists can also be interested in the following inventions in the area of nanotechnologies: a method to obtain a mixture of micro- and nanoparticles of binary alloys, hydrocatalytic processes of recycling heavy oil fractions with the use of perspective nanosize catalysts, a method to produce graphene oxide, a method to decrease electrization of liquid hydrocarbons when applying them, a method to produce composite material boron-carbon, Modeling of static mixer (oil – water) performance for oil desalting and development test, a method of chromatographic separation of single layer carbon nanotubes by chirality and other.
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Nanotechnologies: a review of inventions and utility models. Part II
Статья научная
A brief review of patents is given. The research performed by scientists, engineers and specialists in the area of nanotechnologies and nanomaterials resulted in increased efficiency of construction, housing sector and adjacent fields of economy.For example, an invention «A method to produce metal-polymer nanocomposite materials with metal nanoparticles» refers to the method used in production of polymer articles with nanoparticles of silver or copper, widely applied in different engineering areas and used as antibacterial material. The invention provides environmental responsible and reagentless method to obtain polymer articles with metal nanoparticles which size is 5–15 nm and boosts rangeof polymers, including hemicrystalline and amorphous glass-like ones. The invention «Exfoliated polyurethane nanocomposite with polyfluoroalkyl groups» refers to design of composite and nanocomposite materials and can be used to create materials applied in polymer industry, in particularly, in production of solidcoatings for sport facilities, hydroinsulation and roof coatings, construction sealers and tribotechnical articles. The specialists can also be interested in the following inventions in the area of nanotechnologies: a method to obtain metal nanopowder from lead bronze wastes in distilled water, a method to produce collector plates, a water defluoridation method,an exfoliated polyurethane nanocomposite with polyfluoroalkyl groups, amultifunctional grease lubricant for heavy loaded friction joint, a thermostatic system to perform nanocalorimetric measurements, a self-hardening composition based on polydimethylsiloxane et al.
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Nanotechnologies: a review of inventions and utility models. Part III
Статья научная
The article provides an abstract review of patents. The results of creative activity of scientists, engineers and specialists, including inventions in the field of nanotechnology and nanomaterials, being implemented, allow achieving a significant effect in construction, housing and community services, and related sectors of the economy. For example, the invention «Raw mixture for production of fine-grained polymer concrete modified by microsilica» refers to construction and can be used in manufacture of nanomodified concretes based on potentially chemically reactive coarse and/or fine filler for transport, industrial and civil construction. Modification of cement stone structures by means of microsilica made of silica production wastes and acrylic dispersion will make it possible to intensify hydration of binder, to reduce cement consumption and to increase strength characteristics of final product compared to traditional concrete mixtures. The invention can be used to produce concrete articles and structures, flagstones, decorative borders, to arrange top layers of road beds and to repair them when it is required, as well as to fill cracks and as a filler in sealing joints. The specialists can also be interested in the following inventions in the area of nanotechnologies: nanomodified high-strength light concrete, combined heat-insulating system, composite layered self-healing material, a method to produce metal/carbon nanocomposites, an electrochemical method to produce nanosized powder of metal silicide, a method to produce metal-polymer nanocomposite materials with metal nanoparticles et al.
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Nanotechnologies: a review of inventions and utility models. Part IV
Статья научная
The article provides an abstract review of patents. The results of creative activity of scientists, engineers and specialists, including inventions in the field of nanotechnology and nanomaterials, being implemented, allow achieving a significant effect in construction, housing and community services, and related sectors of the economy. For example, the invention “Heat-insulating material based on air gel” can be used to obtain heat-insulating materials for a wide range of applications. The required technical result, which consists in improving the thermal insulation properties of the material in a wide temperature range, increasing the absorbing properties of electromagnetic radiation in the IR spectrum, increasing the mechanical strength and flexibility, as well as reducing crumbling, is achieved in an air gel-based material containing a fibrous substrate with a density of 0.001–0.1 g/cm3, consisting of silica and/or glass and/or basalt fibers with a diameter of 0.1–5 microns, which is impregnated with an air gel obtained on the basis of silicon dioxide from alkoxysilane with the introduction of a gelling agent and followed by supercritical drying. The introduction of nanomaterials gives an additional reinforcing effect, which increases the mechanical strength of the final material and significantly reduces the crumbling of the air gel. The final material can be provided with an additional layer of fibrous substrate to increase its vibration resistance. This is especially true when using the proposed material for civil and industrial construction in seismically active zones, as well as in aircraft and rocketry. The specialists can also be interested in the following inventions in the area of nanotechnologies: nano-coating protection method for electrical connectors, preparation method of nanometric size metal oxide additives that reduce the temperature of sintering, raw material mixture for the manufacture of fine-grained polymer concrete (modified with microsilica), installation for the synthesis of carbon-containing nanomaterials, a method for producing silver nanoparticles, a method for producing nanocrystalline cubic tungsten carbide, a composition with carbon nanotubes for obtaining a carbon blank for high-density SiC/C/Si ceramics and a method for producing articles from SiC/C/Si ceramics, composite membrane for drying natural and technological gas mixtures based on graphene oxide intercalated with hydroxylated fullerene derivatives, compositions containing nanometric copper, carbon-ceramic fiber-reinforced composite material and a method for its production, a method for producing nanoparticles of aluminum oxide et al.
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Nanotechnologies: a review of inventions and utility models. Part V
Статья научная
The article provides an abstract review of patents. The results of creative activity of scientists, engineers and specialists, including inventions in the field of nanotechnology and nanomaterials, being implemented, allow achieving a significant effect in construction, housing and community services, and related sectors of the economy. For example, the invention «A method to produce dry construction mixtures» refers to manufacturing of building materials, in particularly, to manufacture of dry construction mixtures (DCM) by the method of joint mechanoactivation of cement and dolomite, with further modification of them with carbon nanostructures (CNT). The technical result of the given method of mixing CNT and main component of dry construction mixtures - cement – is that it makes possible to use microquantities (0.005%) of CNT in DCM. That allows decreasing product cost of obtained mixture. Moreover, due to increased strength, faster hardening of materials one can reduce consumption of these mixtures. That is additional factor affecting decrease of mixture product cost. The results obtained after application of mechanoactivation of basic mixture components were different practically by all indicators from the mixtures prepared by simple mixing. Compression strength and tensile strength increased by 10–15%, adhesion strength increased too. Along with increasing of strength characteristics such an important indicator of DCM as air permeability has decreased. Reduction of total volume of pores in dense structure of cement matrix caused dramatic slow-up of moisture diffusion rate. The specialists can also be interested in the following inventions in the area of nanotechnologies: a method of laser building-up welding for metal coatings, high RAP in WMA surface mixture containing nanoglass fibers, a device to apply nanoparticles of metal oxides on metal surface under normal conditions, multifunctional nanostructured additive for coatings, experimental assessment of cement mortar using nanooxide compounds, a composition for setting constructional layers of road pavements, a method to obtain composite films of nanofibers, nano-engineering of construction materials using molecular dynamics simulations, cast and self-compacting concrete mixture for cast-in-situ concrete and prefabricated reinforced units, a method to obtain photocatalyst based on nanotubular titanium dioxide et al.
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Nanotechnology in Construction: State of the Art and Future Trends
Статья научная
The construction industry has long been regarded asenergy-intensive and high pollution industry. The emergence of nanotechnology provides an ideal solution for the construction industry to energy saving and consumption reduction. The introduction of nanotechnology has greatly promoted the development of new green building materials and brought huge economic and social benefits. This paper applies bibliometric analysis to review the nanotechnology-construction research collected by Web of Science database during 2000–2020, and further visualize their literature characteristics. At the global level, the number of literatures on nanotechnology-construction research has been on the rise in 2000-2019, although it has experienced a small decline in individual years. At the national level, the United States has become the global leader in nanotechnology-construction research with 63 articles, far more than other countries. Considering the income gap, developed countries play an indispensable role in the global nanotechnology-construction research system, while the role of developing countries is relatively weak. We found that the existing nanotechnology-construction research mainly focused on the fields of chemistry and materials science. According to the frequency of keywords, the research focus of nanotechnology-construction research mainly focused on the development and application of new building materials. It is concluded that with the extensive attention of researchers, the future research on nanotechnology-construction will continue to appear and increase at increasing rate.
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Статья научная
Introduction. Currently, both abroad and in Russia, there is a “general digitalization” not only of certain types of activities, but also of objects of the technosphere, for example, “smart houses”, “safe cities”, etc. However, the “creators” of these objects violated the main principle of automation of Academician V.M. Glushkov, which says: you cannot automate the mess! Therefore, the authors of this article made an attempt to “eliminate clutter” in the automation of engineering systems in the residential sector. Methods, models and tools. Based on the analysis of the engineering systems of multi-apartment residential buildings and individual residential buildings, as a result of the functioning of which not only the delivery of “life support benefits” is carried out, but also fire-energy and environmental damage occurs, a methodology for “intellectualization” of the accounting means for the supplied resources has been developed for diagnostics and suppression of fire and energy harm with the help of modern nanotechnology and, thus, prevention of fires and explosions in the residential sector. Results and discussion. The methodology of “intellectualization” is based on the results of a system analysis of the “functioning of the residential sector” (apartment buildings and individual residential buildings), which made it possible to “discover” the dialectical unity of benefits and harms from consumed energy resources (electricity, domestic gas, hot and cold water), as well as to carry out a systemic synthesis of nanotechnologies and means of “isolation and suppression” of fire and energy harm. The novelty of the research is protected by RF patents. Conclusion. The proposed approach allows “eliminating the disorder before the automation” of engineering systems of multiapartment residential buildings and individual residential buildings, by “intellectualizing” metering devices and optimizing nanotechnologies for suppressing fire and energy harm that brings socio-economic losses.
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Статья научная
Introduction. At present, both abroad and in Russia, accidents, fires and explosions in the engineering systems of multiapartment residential buildings and individual residential buildings have become more frequent. At the same time, the "creators" of automated systems for monitoring and accounting of energy resources (ASKUE) did not attend to the solution of the problems of safety of engineering systems, since their goals were exclusively commercial tasks – "digitalization" of energy consumption metering and detection of illegal consumption of such sources. Therefore, in this article, an attempt is made to "eliminate clutter" in the automation of engineering systems in the residential sector. Methods, models and tools. Based on the analysis of engineering systems of multi-apartment residential buildings and individual residential buildings, as a result of the functioning of which not only the delivery of life support resources (gas, cold and hot water, electricity, communications, etc.) is carried out, but also fire-energy and environmental harm occurs, a methodology has been developed for the "intellectualization" of the means of accounting for the supplied resources, for the purpose of diagnosing and suppressing fire-energy harm using modern nanotechnologies and, thus, preventing accidents, explosions and fires in the residential sector. Results and discussion. The methodology of "intellectualization" is based on the dialectical unity of benefits and harms from consumed energy resources (electricity, domestic gas, hot and cold water), as well as to carry out a systemic synthesis of nanotechnologies and means of "detection and suppression" of fire-energy harm. The novelty of the research is protected by RF patents. Conclusion. The proposed approach makes it possible to "eliminate the disorder before the automation" of engineering systems of multi-apartment residential buildings and individual residential houses, by "intellectualizing" metering devices and optimizing nanotechnologies for suppressing fire-energy harm which leads to socio-economic losses.
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New Protective Coatings Based on Sulfur Nanoparticles Produced from Potassium Polysulfide
Статья научная
Introduction. Impregnation with a new solution based on potassium polysulfide showed excellent results in the hydrophobization of cement stone and cement-sand mortar due to the formation of a nanoscale water-repellent coating on the surface of the pores from sulfur nanoparticles formed as a result of the destruction of the molecule during the drying process. An innovative solution based on potassium polysulfide refers to polysulfur compounds, from which, as a result of the destruction of polysulfide molecules, a nanoscale layer of sulfur particles is formed on the surface. Materials and research methods. Potassium polysulfide solutions of different densities were used for impregnation; the properties of the solutions were tested on cubic samples with a 40 mm edge, made on the basis of cement and cement-sand mortar. Particle characteristics were evaluated using a laser particle size analyzer, an electron microscope and a diffractometer. Results. The analysis showed that the average size of the particles forming the protective coating is 20 nm, they have a spherically symmetric shape and crystallize into an orthorhombic crystal lattice structure. The treatment of concrete with a solution of potassium polysulfide ensures the formation of a coating based on nanosized sulfur on the surface of the pores of the stone, which partially fills the pore space and, being hydrophobic, reduces the water absorption of samples by 2–3 times, and the water absorption of samples impregnated under vacuum for 0.5 hours, decreases to values of 1.3–1.9%. Results and discussion. Modification of concrete with an impregnating composition developed by us with a solution based on potassium polysulfide The impregnating solution based on potassium polysulfide is stable in the concentration range of 1.15–1.35 g/cm3; upon impregnation, it penetrates into the pore structure of concrete at a level of up to 4 cm or more, depending on the growth and structure of the sample. When the material dries in its pores, sulfur nanoparticles crystallize from the polysulfide solution, partially filling the pore space and forming a protective durable insoluble hydrophobic coating that makes it difficult for water to penetrate into the pores of concrete, but retains its vapor permeability, which is important for wall and facing materials. Conclusions. Impregnation of road building materials and concrete products with a composition based on potassium polysulfide improves their performance properties, increases durability and resistance to weathering, which makes it possible to recommend it for use in the climatic conditions of the Russian Federation.
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Ni-SiC composite coating obtained by electrodeposition
Статья научная
Introduction. One of the common types of coatings is a composite coating based on nickel reinforced with solid particles of silicon carbide SiC. It has high anti-wear properties and is widely used to increase the strength of the working surfaces of internal combustion engine cylinders. The basic technology for applying the coating is electrodeposition. The quality of the coating is affected by the size of the solid particles. Difficulties in forming a composite arise when moving to a large fraction of 20–25 μm, especially when moving from flat samples to long axisymmetric parts. The aim of the research is to study the technological potential of creating a Ni-SiC coating on flat samples simulating a sector of an axisymmetric part. Methods and materials. The research part of the work was carried out on samples of aluminum alloy AK7. Electrodeposition mode: current density 10 A/dm2; duration 60 minutes; temperature 60 °С. The microstructure of the coatings was studied using an Olympus GX51 optical microscope. Coating wear resistance tests were performed using a CSM Micro-Scratch Tester. Microhardness was assessed using a DuraScan 50 microhardness tester. Roughness Ra was determined using a Mitutoyo Surftest profilometer. Results and discussion. The article considers the features of the process of forming a composite coating based on Ni-SiC by the electrodeposition method. A model of the action of electrostatic, gravitational and centrifugal forces on SiC particles in the electrolyte solution for electrodeposition is presented. Based on the model, an installation was designed, on which the technological process of applying a composite Ni-SiC coating to flat samples of aluminum alloy AK7, simulating a sector of an axisymmetric part, was successfully tested. Due to the possibility of rotating the installation during the electrodeposition, three types of coating were obtained: nickel-based «Ni»; nickel-based with silicon carbide particles ”Ni-SiC”; layered coating. Conclusion. The nickel coating with a uniform distribution of SiC particles is characterized by the maximum microhardness value, increased roughness and a small groove width after the scratch test, which indicates good adhesion to the substrate material.
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Obtaining corrosion inhibitors containing synergistic nanoadditives
Статья научная
Introduction. Construction materials, products and structures, and primarily their surfaces, during long-term operation have been destroying mainly as a result of two types of impact: corrosive, associated with the influence of an external, aggressive environment on the material, and erosive, caused by mechanical action. An effective and widely used means of protection against corrosion is the use of inhibitors The search for effective methods of anticorrosion protection of metals and alloys is due to the great damage caused by corrosion, not only in technological or economic terms. No less dangerous is the deterioration of the ecological situation caused by the ingress of corrosion products or toxic reagents into the environment. The leading place among corrosion inhibitors is occupied by heterocyclic compounds, namely, nitrogen-containing compounds, in particular imidazoline derivatives. Methods and materials. We synthesized 2-amylidenehydrazinoimidazolinone-4n aminoguanidine, on the basis of which we obtained anticorrosion compositions with the addition of nanoadditives – derivatives of unsymmetrical triazines. Results. The synthesized anticorrosive compositions were tested by electrochemical and gravimetric methods in acidic and model environments. Conclusion. The obtained compounds have a protective ability, and the results indicate the promising use of compositions with nanoadditives – derivatives of 1,2,4-aminotriazines as corrosion inhibitors.
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Obtaining new additives for polyvinyl chloride compositions
Статья научная
Introduction. Polyvinyl chloride (PVC) is the world's leading synthetic polymer in industrial use. Products based on PVC have firmly taken on the world market, and currently there is no highly developed country that is able to avoid its production and consumption. The high demand for thermoplastics is primarily due to its unique properties such as durability, resistance to climatic conditions, low flammability, good barrier properties, economy, environmental friendliness and versatility. The complex of technological and service properties of soft PVC, in addition to other additives, is mainly provided by plasticizers, the content of which can reach 50% or more. It is the efficiency of the plasticizing that has a decisive impact on the characteristics in the resulting materials and products. One of the most widely used classes of compounds in the plasticization of PVC are phthalic acid esters, in particular, dibutyl phthalate (DBP), di-(2-ethylhexyl)-phthalate (dioctyl phthalate, DOP), diisononyl phthalate (DINP) and diisodecyl phthalate (DIDP). Phthalates have found the greatest use as plasticizers due to their properties: good compatibility with PVC, low migration from plastic compound, minimal interaction with the polymer at room temperature, good frost resistance, high electrical insulating properties, availability, manufacturability and low cost. Methods and materials. The paper presents methods for the obtaining of novel symmetrical and asymmetric phthalate plasticizers: dibenzoxyethyl phthalates, benzylbenzoxyethyl phthalates, phenoxyethylbenzoxyethyl phthalates, ethoxyoctylbenzoxyethyl phthalates – by catalytic esterification of phthalic anhydride with oxyethylated phenylcarbinols, phenols and 2-ethylhexanols. The conditions for the synthesis of target products with the maximum yield were selected. The physicochemical properties of the obtained compounds were studied. The obtained experimental data were used to identify promising novel plasticizers of the phthalate type by cluster analysis. Cluster analysis for decision making is the most effective, as it is designed to combine some samples into classes (clusters) in such a way that the most similar in properties get into one cluster, but at the same time, samples of different clusters differ from each other as much as possible. Clustering carried out in the program Statistica 10. Results and discussion. According to the data obtained, it is found that benzylbenzoxyethyl phthalates and ethoxyoctylbenzoxyethyl phthalates have the best characteristics in terms of plasticizing ability. We study the influence of the selected plasticizers on the physical and mechanical characteristics of PVC compositions The effectiveness of compounds in the PVC composition is evaluated in terms of “elongation stress” and “breaking stress”. The test results of the samples are compared with the indicators of PVC compounds containing DBP. Conclusion. The use of the developed additives contributes to the production of PVC compounds with improved physical and mechanical characteristics.
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Obtaining new phthalate plasticizers
Статья научная
Introduction. The increase in production volumes and the expansion of the scope of application of polyvinyl chloride (PVC) compounds contributes to the development of new additives and the attraction of new sources of raw materials for their production. The most important additives necessary for processing PVC are plasticizers. Plasticizers market is one of the largest segments of the global additives market. Since plasticizers are the most simple, cheap and affordable way to modify various properties of the polymeric compositions, their role in processing polymeric materials has recently increased significantly. In application the ester plasticizers, capable to plasticize almost all polymers, especially polyvinylchloride are considered as the most practical. Currently, the industry has mastered production of more than three hundred brands of plasticizers, most of which are esters of phthalic acid. Traditional phthalate plasticizers are the most widely used all over the world. Materials and methods. The paper describes the esterification reactions of phthalic anhydride with oxyethylated (degree of oxyethylation 1.2) and oxypropylated (degree of oxypropelation 1.1) cresols. New symmetric and asymmetric phthalate plasticizers were obtained – dikresoxycresylphthalate, butoxyethylcreoxyethylphthalate, cresylcresoxyethylphthalate and cresylcresoxypropylphthalate, optimum conditions for their preparationare picked up, studied their physical and chemical properties. The obtained experimental data were used to identify promising new phthalate-type plasticizers by the method of cluster analysis. Cluster analysis is the most effective method for solving this problem, because it is intended for combining some samples into classes (clusters) in such a way that the most similar in properties fall into one cluster, but at the same time the samples of different clusters differ as much as possible from each other. Clustering was carried out using the Statistica 10 program. Since at present the reference plasticizer is dioctylphthalate (DOP), the test results of the samples were compared with those of PVC compositions containing DOP. Results and discussions. According to the data obtained, it was found that butoxyethylcreoxyethyl phthalate has the best characteristics in terms of plasticizing ability. The influence of the selected plasticizer on the technological characteristics of PVC-compounds has been studied. The efficiency of the synthesized butoxyethylcreoxyethylphthalate in the PVC composition was evaluated by the indicator (index) of melt flow rate (MFR) and by the indicators of “thermal stability” and “color stability”. Conclusion. Use of the developed additive contributes to the production of PVC compounds with improved rheological characteristics, increased heat resistance and color stability.
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Obtaining the retainer for waterproofing road bitumens
Статья научная
Bitumen is a mixture of hydrocarbons and hetero-organic compounds. It is one of the most popular building materials today. Due to the growing consumption of bitumen for various purposes, the requirements for its quality characteristics are increasing, which prompts a comprehensive study of the physical and mechanical properties and methods of its modification. Currently, various additives are used, from inorganic materials to organic binders, including waste chemical, petrochemical and household industries. These additives create a nanodispersed structure inside the bitumen, which provides a change in the physical and mechanical properties in the required direction. Methods and materials. The work proposes a method for obtaining a fixer for waterproofing road bitumen based on nitrogen-containing organic compounds. The goal of research is to study the effect of the additive-derivative of triethylenediaminedicyan, which leads to the formation of a nanodispersed structure of bitumen of the “sol-gel” type, the quality indicators of which will meet the requirements of the new standard GOST 33133-2014 “Viscous road oil bitumen”. The object of the study is the bitumen production unit of workshop No. 14 of Gazprom neftekhimSalavat LLC, designed to produce commercial bitumen: oil road grades CB 90/130 in accordance with GOST 22245-90, used in road, civil and industrial construction as a binder and waterproofing material. Results and discussion. In the course of the study, the nature of the interaction and the effect of the modifier on the properties of bitumen, which ensure the production of nanostructured bitumen of the “sol-gel” type, were revealed. As a result of the study, a comparative assessment of the effect of the fixer on the properties of waterproofing bitumen revealed a significant improvement in physical and mechanical properties in comparison with bitumen grade CB 90/130. Conclusion. The obtained compound based on triethylenediaminedicyancan can be used as a fixing additive to road bitumen
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