Thermodynamic Study of Fire-Protective Material

2021 ◽  
Vol 1038 ◽  
pp. 486-491
Author(s):  
Anton Chernukha ◽  
Andrii Chernukha ◽  
Pavlo Kovalov ◽  
Alexander Savchenko

The paper considers the material for the protective coating of building structures made of wood. The possibility of chemical processes occurring in the material leading to its expansion has been studied. The coefficient of expansion of the material when heated is practically established. It has been established that the material can swell, both under the influence of flame and when the temperature rises at a low speed. Swelling coefficient at the same time it reaches 8. The temperature range of swelling is 150–250 С, which is confirmed by thermodynamic calculations and experimentally. The temperature at which the material begins to swell is lower than the temperature of thermal destruction of wood.

2014 ◽  
Vol 783-786 ◽  
pp. 584-590 ◽  
Author(s):  
Kalenda Mutombo ◽  
C. Siyasiya ◽  
W.E. Stumpf

Ti6Al4V samples were isothermally compressed using a Gleeble(TM) 1500D thermo-mechanical simulator. Differential scanning calorimetry (DSC), microstructural analyses, and thermodynamic calculations were used to investigate the sequence of transformation of β into α or vice-versa and the presence of different phases in the compressed Ti6Al4V sample. Globular alpha phase was revealed in the isothermally compressed sample in addition to martensitic and lamellar α/β structures. The transition temperature range of β into α-phase was determined using the DSC thermograms and thermodynamic calculated diagrams. The fraction of α-phase globulized increased as the strain rate decreased from 0.01s-1 to 10-3s-1, and the spheroidization of the α-phase is only possible in a specific range of deformation temperatures.


2018 ◽  
Vol 788 ◽  
pp. 36-44
Author(s):  
Liudmyla Demydchuk ◽  
Dmytro Sapozhnyk

The normative documents of Ukraine (DBN V.1.1.7 ̶ 2016) [1] establish that the limit of fire resistance of reinforced-concrete building structures is determined by the calculation method or by fire tests, and shall be at least 45 minutes. Taking into account the modern construction technologies, namely, the reduction of the section of the main building reinforced-concrete structures, it is expedient to use fire-retardant coatings to provide the necessary fire resistance limit.


Molecules ◽  
2019 ◽  
Vol 24 (17) ◽  
pp. 3075
Author(s):  
Svetlana Yefremova ◽  
Abdurassul Zharmenov ◽  
Yurij Sukharnikov ◽  
Lara Bunchuk ◽  
Askhat Kablanbekov ◽  
...  

Lignin processing products have an extensive using range. Because products properties depend on lignin precursor quality it was interesting to study lignin isolated from rice husk being a large tonnage waste of rice production and its structural transformations during carbonization. Lignin isolated by the thermal hydrolysis method with H2SO4 1 wt % solution and its carbonized products prepared under different carbonization conditions were characterized using elemental analysis, IR, TPD-MS, XRD, TEM, and EPR. It was shown lignin degradation takes place over the wide (220–520 °C) temperature range. Silica presenting in lignin affects the thermal destruction of this polymer. Due to the strong chemical bond with phenolic hydroxylic group it decreases an evaporation of volatile compounds and as a result increases the temperature range of the lignin degradation. Rice husk hydrolytic lignin transformations during carbonization occur with generation of free radicals. Their concentration is decreased after condensation of aromatic rings with carbon polycycles formation, i.e., the graphite-like structure. Quantity and X-ray diffraction characteristics of the graphite-like phase depend on carbonization conditions. Morphology of the lignin-based carbonized products is represented by carbon fibers, carbon and silica nanoparticles, and together with another structure characteristics provides prospective performance properties of lignin-based end products.


1991 ◽  
Vol 11 (2) ◽  
pp. 71-81 ◽  
Author(s):  
Yu. N. Zhitnev ◽  
A. V. Zakharchenko ◽  
N. Yu. Mordkovich ◽  
T.-B. H. Nugaev ◽  
E. A. Tveritinova ◽  
...  

The Pulsed Homogeneous Laser Pyrolysis (PHLP) of CHClF2 initiated by IOP(20) radiation of TEA-CO2 laser was carried out in the presence of SF6 sensitizer with the mixture components ratio 1:1 under partial pressure of the reactant equal to 1 Torr and 2 Torr.To describe PHLP process in the afterpulse period we suggested a kinetic model of CHClF2 thermal destruction accounting for the inhomogeneity of laser heating of the reaction mixture and its further cooling by the heat conduction mechanism. Applying the standard mathematical procedure for matching the experimental results of the degree of reactant destruction, and the numeric computations of this value made according to the suggested model, the Arrhenius parameters of the reaction of CHClF2 monomolecular conversion in the temperature range of 1000–1200 K were unambiguously determined. The values were obtained for the activation energy Eα = 52.8 ± 0.3 kcal/mol, and the pre-exponential factor A = (2.5 ± 1) · 1012 s−1.


2008 ◽  
Vol 53 (4) ◽  
pp. 663-670 ◽  
Author(s):  
D. V. Kostomarov ◽  
Kh. S. Bagdasarov ◽  
S. A. Kobzareva ◽  
E. V. Antonov

2012 ◽  
Vol 14 (4) ◽  
pp. 77-82 ◽  
Author(s):  
Piotr Michorczyk ◽  
Kamila Zeńczak ◽  
Rafał Niekurzak ◽  
Jan Ogonowski

Abstract Dehydrogenation of propane in the presence of CO2 was considered as an alternative to commercial dehydrogenation pathway of obtaining propene and the new sources of synthesis gas. Based on thermodynamic calculations and a catalytic tests it was shown that by controlling CO2 concentration in the feed the molar ratio of H2/CO (synthesis gas) in the products mixture can be regulated. Several different pathways of DHP-CO2 process integration with commercialized chemical processes utilized synthesis gas were proposed


Author(s):  
Степан Петрович Михайлов ◽  
Михаил Геннадьевич Сульман ◽  
Валентин Юрьевич Долуда ◽  
Валентина Геннадьевна Матвеева

Представленная статья посвящена сравнительному анализу теоретических основ синтеза N-метилглюкамина (основание Шиффа) и экспериментальных данных. N-метил-D-глюкозимин, это промежуточный продукт получения N-метил-D-глюкозамина, широко используемого в фармацевтике, в качестве балластного вещества или противоиона, улучшающего биодоступность основного лекарственного средства. Проведена оценка кинетических параметров синтеза, рассчитан максимальный достигаемый выход. Применение термодинамических расчетов позволяет оценить влияния условий проведения химических процессов на выход целевых продуктов, а это способствует более глубокому пониманию механизмов протекания химических реакций. В представленной статье приводятся результаты термодинамических расчётов реакции синтеза N-метил-D-глюкозимина методом Ван-Кравлена - Черемнова. Рассчитаны энергия Гиббса, константы равновесия и конверсия глюкозы при единичной активности реагирующих веществ. Показано, что увеличение температуры реакционной массы с 20 до 160°С способствует увеличению конверсии глюкозы с 3 до 32%, в связи с чем можно рекомендовать проведение этой реакции при повышенных температурах. The presented article is devoted to a comparative analysis of the theoretical foundations of the synthesis of N-methylglucamine (Schiff's base) and experimental data. N-methyl-D-glucosimine is an intermediate in the preparation of N-methyl-D-glucosamine, which is widely used in pharmaceuticals, as a ballast or counter-ion to improve the bioavailability of the main drug. The kinetic parameters of the synthesis were estimated, and the maximum attainable yield was calculated. The use of thermodynamic calculations makes it possible to evaluate the influence of the conditions of chemical processes on the yield of target products, and this contributes to a deeper understanding of the mechanisms of chemical reactions. This article presents the results of thermodynamic calculations of the reaction for the synthesis of N-methyl-D-glucosimine by the Van Cravlen - Cheremnov method. The Gibbs energy, equilibrium constants, and glucose conversion were calculated for a single activity of the reacting substances. It was shown that an increase in the temperature of the reaction mixture from 20 to 160 ° C promotes an increase in the conversion of glucose from 3 to 32%, and therefore it is possible to recommend carrying out this reaction at elevated temperatures.


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