Inorganic Polymeric Materials Based on Natural Silicate and Aluminosilicate Raw Materials

2022 ◽  
Vol 906 ◽  
pp. 1-6
Author(s):  
Emma Sahakyan ◽  
Avetik Arzumanyan ◽  
Nelli Muradyan

The prospects of implementing the mechanochemical activation method of volcanic silicate and aluminosilicate rocks - perlites, tuffs, pumice, etc. are being considered for the production of a wide range of building materials using energy-conserving technologies. The thermodynamic and kinetic parameters of interaction in the systems of aluminosilicate – NaOH have been presented, indicating low-temperature sintering of volcanic rocks with sodium hydroxide. According to the degree of activity, the rocks have the following order: perlites, tuffs, obsidian, microcline. Kinetic parameters are presented: concentration, temperature, conversion degree, reaction rate constant, time of complete reaction and product layer thickness.

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3497
Author(s):  
Piotr Stachak ◽  
Izabela Łukaszewska ◽  
Edyta Hebda ◽  
Krzysztof Pielichowski

Polyurethanes (PUs) are a significant group of polymeric materials that, due to their outstanding mechanical, chemical, and physical properties, are used in a wide range of applications. Conventionally, PUs are obtained in polyaddition reactions between diisocyanates and polyols. Due to the toxicity of isocyanate raw materials and their synthesis method utilizing phosgene, new cleaner synthetic routes for polyurethanes without using isocyanates have attracted increasing attention in recent years. Among different attempts to replace the conventional process, polyaddition of cyclic carbonates (CCs) and polyfunctional amines seems to be the most promising way to obtain non-isocyanate polyurethanes (NIPUs) or, more precisely, polyhydroxyurethanes (PHUs), while primary and secondary –OH groups are being formed alongside urethane linkages. Such an approach eliminates hazardous chemical compounds from the synthesis and leads to the fabrication of polymeric materials with unique and tunable properties. The main advantages include better chemical, mechanical, and thermal resistance, and the process itself is invulnerable to moisture, which is an essential technological feature. NIPUs can be modified via copolymerization or used as matrices to fabricate polymer composites with different additives, similar to their conventional counterparts. Hence, non-isocyanate polyurethanes are a new class of environmentally friendly polymeric materials. Many papers on the matter above have been published, including both original research and extensive reviews. However, they do not provide collected information on NIPU composites fabrication and processing. Hence, this review describes the latest progress in non-isocyanate polyurethane synthesis, modification, and finally processing. While focusing primarily on the carbonate/amine route, methods of obtaining NIPU are described, and their properties are presented. Ways of incorporating various compounds into NIPU matrices are characterized by the role of PHU materials in copolymeric materials or as an additive. Finally, diverse processing methods of non-isocyanate polyurethanes are presented, including electrospinning or 3D printing.


2020 ◽  
Vol 992 ◽  
pp. 253-258
Author(s):  
M.P. Lebedev ◽  
V.N. Tagrov ◽  
E.S. Lukin

The article deals with the manufacture of modern structural ceramic materials from clay and loam deposits of the Republic of Sakha (Yakutia). The importance and relevance of the development of the production of building materials from local raw materials is emphasized, since this will certainly affect the effectiveness of the construction complex as a whole. The successful development of the construction complex is capable of not only stimulating growth in all sectors of the economy, but also contributes to solving the most pressing social problems. Today, Yakutia has huge reserves of mineral raw materials for the production of a wide range of building materials and products. Of practical interest are wall materials made from clay soils. Given the features of the region’s raw material base, this work focuses on additional processing of traditional material. Controlling the complex physicochemical and structural-mechanical transformations that occur during heat treatment, a methodology has been developed for creating a composite material that will allow competitive innovative materials with enhanced strength properties to be produced with a reinforcing element with a glassy phase matrix of mullite crystals. The fabricated samples have a wide range of physical and mechanical properties and allow using it as a high-quality structural building ceramics, as well as industrial floor technical tile.


2020 ◽  
Vol 175 ◽  
pp. 11022
Author(s):  
Daria Buzina ◽  
Igor Engovatov

Natural radionuclides include the 238U and 232Th radioactive families with daughter decay products and 40K potassium. In addition to these, the raw materials may contain man-made radioactive nuclides formed due to accidents at the nuclear facilities and its uncontrolled release into the environment (for example, 137Cs). Reducing the impact of radiation exposure on humans and the environment is an urgent task, both in Russia and abroad, given the rapid quantitative growth of the range, manufacturers, suppliers and consumers of building materials associated with the general trend of urbanization. Currently, there is a large number of studies on the natural and man-made radioactivity of building materials. As a rule, they present disparate and local scientific results, which complicates their accessibility to a wide range of interested parties manufacturers and consumers of construction products. Therefore, it is necessary that information on the radiation and environmental cleanliness of various materials and products was easily accessible to all comers. An information system on the natural and man-made radioactivity of building materials and products should become a tool for solving this problem. The work outlines the principles of creation and practical implementation, structure and content, goals, objectives of the field of destination and application of the information system for natural and man-made radioactivity of building materials and products.


Author(s):  
Bohdan Murashevych ◽  
Volodymyr Toropin ◽  
Dmytro Stepanskyi ◽  
Hanna Maslak ◽  
Kostyantyn Burmistrov ◽  
...  

A method has been developed for the synthesis of granular polymeric materials with immobilized N-chloro-sulfonamide groups. Commercially available resin polymers widely applied for the preparation of ion exchangers have been used as polymer carriers. The elaborated technological conditions make it possible to modify these resins with a high conversion degree, without deteriorating the strength characteristics, and with the possibility of regulating the concentration of active chlorine over a wide range (up to 11 % w/w). The structure of the synthesized polymers was confirmed by IR spectroscopy data. To determine the concentration of functional groups, a special method of iodometric titration has been developed. The processes of emission of active chlorine from synthesized polymers into aqueous solutions have been studied. It has been shown that this process significantly depends on the composition of the solution: no release of active chlorine into distilled water is observed, and when using tap water, its concentration is reached 5–8 mg/dm3 and remains up to 30 days when the granules are in water. The processes of activation of active chlorine emission by compounds of amine nature have been studied, the corresponding kinetic curves of the dependence between change in the concentration of active chlorine in solution and the used activator are presented. It has been found that the nature of the used activator strongly affects, among other things, the stability of the obtained chlorine-active solutions. Taurine and sulfamic acid are found to be the optimal activators for obtaining stable solutions of active chlorine of high concentration. The composition of the N-chloro-taurin solution obtained in this way has been additionally analyzed by UV spectroscopy. Thus, the synthesized polymers make it possible to quickly in situ obtain high-purity solutions of active chlorine without the use of special electrochemical equipment. The polymers themselves are compact, stable, and can be repeatedly regenerated


2021 ◽  
Vol 340 ◽  
pp. 01003
Author(s):  
Liliya Berdnikova ◽  
Fedor Gorbunov ◽  
Andrey Lapin

The results of research on the development of compositions of construction materials for structural purposes based on technogenic waste and mineral raw materials are presented. The possibility of obtaining materials with a wide range of operational properties by the methods of slip casting (compressive strength of the samples based on chamotte and sand is 53.0–95.9 and 50.0-69.5 MPa, bending strength is 8.1–16.5 and 8.5–15.3 MPa, abrasion is 0.2–0.36 and 0.15–0.39 g/cm2, respectively) and semi-dry pressing (compressive strength of the samples based on chamotte and sand are 19.1–43.5 and 18.3–32.6 MParespectively) isdemonstrated.


2020 ◽  
Vol 12 (4) ◽  
Author(s):  
Nadezhda Manakova

Substantial volumes of tailings and waste rocks placed in dumps create serious environmental and economic damage in mining areas and adjacent territories. The development of technologies for processing waste into heat-insulating building materials (foam glass) will make it possible to reduce the burden on the environment, as well as reduce the cost of finished building products. The article substantiates the possibility of obtaining block foamed materials for the production of heat-insulating materials based on man-made waste using low-temperature technology. The author investigated the ways of improving the operational properties of foam silicates by introducing modifying additives (apatite-nepheline waste, fly ash). To obtain foam silicates based on silica-containing waste, a liquid glass composition was prepared, into which additives were introduced. After molding and drying, the samples were swollen. Physical, chemical and thermal properties of foamed silicate materials made of silica-containing raw materials were determined taking into account the requirements of GOST for thermal insulation construction materials. To determine the thermal conductivity coefficient, an ITP-MG 4 electronic thermal conductivity meter was used. Microscopic studies were carried out using a SEM LEO 420 scanning microscope. The author of the article proposes the optimal compositions and conditions for obtaining foam materials that meet the regulatory requirements for materials and products for building insulation. Foamed materials with density up to 0.55 g/cm3, strength 5.5 MPa, water absorption 15–22 %, thermal conductivity 0.09–0.104 W•m/K were obtained. Foam glass materials have a wide range of properties: non-flammable, environmentally friendly, have a long service life, and are not subject to mold deterioration. The obtained materials can be recommended for use as thermal insulation in the construction and reconstruction of industrial and civil buildings and structures.


Crystals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 102 ◽  
Author(s):  
Raluca Iștoan ◽  
Daniela Roxana Tămaș-Gavrea ◽  
Daniela Lucia Manea

Interdisciplinary and sustainability represent the main characteristics of this paper due to the fact that this research is offering a connection between two main areas—agronomy and construction, by using hemp shiv for the design of new building materials, which can increase the sustainability level of the building industry. For this reason, the main scope of this study is based on the investigation of a new category of composite building materials—lightweight mortars based on hemp shiv, volcanic rocks and white cement—which contribute to a positive environmental impact and help to increase indoor comfort. A complex report was carried out on two segments. The first one is focused upon the characteristics of the raw materials from the composition of the new materials, while the second segment presents a detailed analysis of these composites including morphological and chemical investigation, pyrolytic and fire behavior, compression and flexural strengths, and acoustic and thermal characteristics. The proposed recipes have as a variable volcanic rocks, while the hemp and the binder maintain their volumes and properties. The results were analyzed according to the influence of volcanic rocks on the new composites.


Author(s):  
V. V. Afanasyev ◽  
V. G. Kovalev ◽  
V. A. Tarasov

The aim of the work is to study the processes of electrothermal gasification of solid fuels in energy technological complexes and to assess the possibilities of using energy technological complexes for regulating load schedules of electric power systems. By the methods of mathematical and physical modeling of physicochemical processes of gasification of solid carbon- containing materials and energy conversion, the main characteristics of electro-technological complexes for the processing of solid carbon-containing materials are obtained. A technological scheme of a maneuverable consumer of electricity and power is proposed, allowing to participate in demand management and increase the efficiency of electric power systems, comprehensively process any solid types of fuels, and build municipal gasification systems for areas that do not have access to natural gas sources. It is shown that the energy potential of the synthesis gas obtained by thermoelectric gasification in electrode installations is several times higher than the cost of electricity for gasification. During the hours of maximum load of the power system, the electrothermal gasifier allows to significantly reduce the consumed active power due to the transition to the autothermal gasification mode without reducing the performance of synthesis gas and work in the “market of system services” as a regulated load. Electrotechnological electrode installation allows the use of cheap electric energy of nighttime minima for the production of synthesis gas and the recovery of ferroalloys from oxides of raw materials and ore materials to be added to the coal recovery process. Electrode electrothermal installation provides a wide range of regulation of consumed electrical power, good process controllability for any type of raw materials, including combustible solid waste. High-temperature reduction processes in electrothermal gasifiers make it possible to process fuel of any composition without enrichment and grinding, to convert the mineral part of solid fuel into slag, which can be used to produce building materials. The oxides of a number of metals contained in the mineral part of the fuel are reduced and form a ferroalloy.


MRS Bulletin ◽  
2004 ◽  
Vol 29 (5) ◽  
pp. 308-313 ◽  
Author(s):  
Karen Scrivener ◽  
Henri Van Damme

AbstractThis article serves to introduce the May 2004 issue of MRS Bulletin on Construction Materials: From Innovation to Conservation. By volume, building materials are by far the most widely used type of materials. The most common construction materials—concrete and wood—are paradigms of complex and hierarchical materials, with a microstructure extending quasi-continuously down to the nanoscale. In the past, most improvements have been obtained by modifying the microstructure at the largest scales, for instance, by reducing the macroporosity. Recent advances in our understanding of the interactions and microstructure development show that the major levers for improvement from now on will rely on surface and colloid science and the science of complex materials, often at the nanoscale. This can lead to remarkable properties, such as self-compaction and ultrahigh strength, and even new functionality, such as self-cleaning through photocatalysis. Construction materials face a wide range of challenges today, many of which are linked to the need for more sustainable development: reducing the consumption of raw materials, reducing the energy used in processing, and increasing service life. In many parts of the world, there is also an increasing need to repair, rehabilitate, and conserve old buildings. The articles in this issue touch on these challenges as well as the advances being made in construction materials through materials research.


2017 ◽  
Vol 33 (1) ◽  
pp. 15-34 ◽  
Author(s):  
Stanisław Porada ◽  
Tadeusz Dziok ◽  
Grzegorz Czerski ◽  
Przemysław Grzywacz ◽  
Andrzej Strugała

Abstract In order to determine the suitability of Polish coals for steam gasification, five Polish hard coals and three brown coals, which are used for power and heat production, were examined in this work. The examinations of the process of steam gasification were conducted with the use of a laboratory plant which allows for measurements within a broad pressure range with the thermovolumetric method. Reactivity evaluations for the examined coals were conducted on the basis of an analysis of the shape of the kinetic curves of formation of major gasification products and a comparison of the curves of the carbon conversion degree of the examined raw materials. In order to evaluate the reactivity of the examined coals, the following factors were utilized: a comparison of the shape of the curves of the carbon conversion degree and the maximal value of the carbon conversion degree, the time of partial conversion τ0.5, the reactivity index R0.5, as well as the reaction rate constant of carbon conversion. The yields, composition and calorific value of the resulting gas were determined as well as the reaction rate constants of formation of particular gaseous products of gasification. Additionally, for the examined coals, ash fusibility and the content of selected impurities, e.g. sulfur, chlorine and mercury, were given.


Sign in / Sign up

Export Citation Format

Share Document