scholarly journals Structural Construction of Binders Based on Orthophosphoric Acid and Refractory Materials

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
R. Liutyi ◽  
D. Liuta ◽  
I. Petryk
Keyword(s):  
Phase Composition ◽  
Thermogravimetric Analysis ◽  
Orthophosphoric Acid ◽  
Phosphate Binders ◽  
Refractory Materials ◽  
Thermal Hardening ◽  
Environment Friendly ◽  
Temperature Range ◽  
Quartz Dust ◽  
Differential Thermogravimetric Analysis

The formation of phosphate binders in systems based on orthophosphoric acid and the most common refractory fillers in foundry technology (quartz dust, zircon ZrSiO4, and kyanite-sillimanite Al2SiO5) has not been previously studied. The phase composition of these inorganic binders was studied, and the formation of silicon SiP2O7 and zirconium ZrP2O7 pyrophosphates was confirmed. The study by differential thermogravimetric analysis in the temperature range of 20–1000°С established the fact that the formed binders are thermally stable and do not emit harmful gaseous substances. The obtained results of the studied binders make it possible to develop new environment-friendly core mixtures of thermal hardening.

scholarly journals Synthesis and Electrochemical Properties of C/LiMnPO4 Cathode Materials by Complex Polymerized Method

2011 ◽  
Vol 485 ◽  
pp. 115-118
Author(s):  
Atsushi Fujita ◽  
Fuminari Isobe ◽  
Takayuki Kodera ◽  
Takashi Ogihara
Keyword(s):  
Thermogravimetric Analysis ◽  
Electrochemical Properties ◽  
Carbon Content ◽  
Discharge Capacity ◽  
Cathode Materials ◽  
Type Structure ◽  
Initial Discharge Capacity ◽  
Initial Discharge ◽  
Differential Thermogravimetric Analysis

C/LiMnPO4 materials were synthesized by the complex polymerized method. An orthorhombic olivine type structure was obtained by calcination at temperatures over 973 K under an argon/hydrogen (5%) atmosphere. Differential thermogravimetric analysis showed that the carbon content of C/LiMnPO4 was about 65 wt%. The initial discharge capacity of C/LiMnPO4 calcined at 973 K was 135 mAh/g at 0.1 C and 60 mAh/g at 1 C.

scholarly journals HEAT-RESISTANT COMPOSITIONS BASED ON WASTE OF ENTERPRISES OF CERAMIC INDUSTRY

2018 ◽  
Vol 8 (4) ◽  
pp. 56-60
Author(s):  
A. I. KHLYSTOV ◽  
D. I. ISAEV ◽  
D. A. PODGORNAYA
Keyword(s):  
Heat Treatment ◽  
Residual Strength ◽  
Ceramic Industry ◽  
Orthophosphoric Acid ◽  
Phosphate Binders ◽  
Critical Temperatures ◽  
Heat Resistant ◽  
Clay Component

The article presents various methods of synthesizing heat-resistant binders based on large-tonnage wastes of the ceramic industry. The use of expanded clay dust in the compositions of heat-resistant concrete on portlandcement allowed to increase their residual strength in the zone of critical temperatures (800-1000 ° C). It was revealed and justifi ed that the use of phosphate binders for synthesizing a binder made it possible to increase the refractoriness of the heat-resistant composition based on expanded clay dust to 1300-1350 с. As the experiments show, claydite dust in its composition contains a clay component, which ensures the plasticity of the ramming mass. It was established that samples of ramming mass on orthophosphoric acid did not require heat treatment and can be immediately removed.

Thermoanalytic interlaboratory experiment for identification of materials, substances and fire protection equipment

2020 ◽  
pp. 15-23
Author(s):  
Игорь Валентинович Архангельский ◽  
Юрий Кузьмич Нагановский ◽  
Игорь Андреевич Годунов ◽  
Николай Владимирович Яшин
Keyword(s):  
Thermogravimetric Analysis ◽  
Fire Protection ◽  
Dispersion Analysis ◽  
Statistical Characteristics ◽  
Single Measurement ◽  
Temperature Range ◽  
Conversion Rates ◽  
Polymer Dispersions ◽  
Parallel Measurements

Проведен межлабораторный термогравиметрический эксперимент по идентификации огнезащитных составов интумесцентного типа. Использование дисперсионного анализа позволило установить значимость/незначимость различий в поведении исследуемых материалов при нагревании, выявить лаборатории, обладающие необходимыми компетенциями для проведения идентификации. Найдено, что применение различных водно-полимерных дисперсий даже близкого строения в составе огнезащитных материалов приводит к неидентичности их свойств. Представленный подход позволил однозначно установить неидентичность исследованных огнезащитных составов. The article deals with the problem of identification of materials, substances and means of fire protection according to GOST R 53293-09 using one of the methods of thermal analysis, namely, thermogravimetric analysis. The long-term practice demonstrated that the methodology presented in the standard did not always give a clear result when identifying objects. Therefore, the evaluation experiment was conducted simultaneously in several testing laboratories with the appropriate equipment. The tests were conducted in the laboratories of the FGBU VNIIPO EMERCOM of Russia, ANO «CISIS FMT», and two CCPS of the Lomonosov Moscow State University. The most complex and controversial objects for identification were studied, namely, thermally expanding (intumescent) flame retardants based on water-polymer dispersions, which are used to protect building structures in closed premises. The purpose of the work consists in more correctly identifying the differences in the samples of the identifier and the analyzed object by using methods of dispersion analysis (GOST R ISO 5725-1, 2-202) when processing the joint interlaboratory experiment. Thermogravimetric analysis of objects was performed in platinum crucibles on samples in the form of disks with a thickness of 0,2-0,3 mm, weight 5-7 mg, at a heating rate of 20 °C/min in the air flow (50-70 ml/min). As a result of the experiment, the significance/insignificance of differences between samples should be displayed. The opinion about the competence of the laboratories participating in the experiment was made. In each laboratory there were conducted two series of thermogravimetric tests in 30-700 °C temperature range including five parallel measurements in each series. Each independent single measurement for further processing was represented by the data array formed within the temperature range of 140-650 °C with a 5° step, in total 103 points in each measurement. The results were processed using Excel spreadsheets. In the context of dispersion analysis there were evaluated both mean values of conversion rates for all laboratories, and the convergence (repeatability) variance for each laboratory using the Student's test, and the inter-laboratory variance (reproducibility variance) using the Cochran’s С test. This procedure revealed the nature of the quasi-samples and established the identity/non-identity of the samples. The results of calculations are represented by the graphical dependence of the generalized average degrees of transformation of destruction processes of objects under the temperature as well as the difference between these characteristics for laboratories I-IV. The presented identification procedure allows both to uniquely solve the problem of significance/insignificance of differences between the test object and the identifier, and to distinguish samples that have a similar composition. The statistical characteristics of a single measurement are calculated. The convergence of parallel measurements for determination of statistical outliers is identified. Determination of the overall average difference for a series of degrees of transformation allows to calculate the Student's test and accept or reject the null hypothesis. The performance of the joint evaluative (interlaboratory) experiment allows not only to establish the significance/insignificance of differences in the behavior of the materials during heating, but also to identify laboratories that have the necessary competencies for identification. The case considered in this paper revealed that the use of various water-polymer dispersions of even close structure in the composition of fire-resistant materials leads to non-identity of their properties.

Polymerization studies: The application of differential thermogravimetric analysis

1993 ◽  
Vol 50 (8) ◽  
pp. 1475-1482 ◽  
Author(s):  
Ivanka G. Popović ◽  
Lynne Katsikas ◽  
Horst Weller ◽  
Susanne Schrötter ◽  
Jovan S. Veliĉkoví
Keyword(s):  
Thermogravimetric Analysis ◽  
Differential Thermogravimetric Analysis

A Study On The Thermal Decomposition of Ba(tmhd)2 and Sr(tmhd)2

1995 ◽  
Vol 415 ◽  
Author(s):  
Hyun-Kyu Ryu ◽  
Jae Hyun Han ◽  
Sang Heup Moon
Keyword(s):  
Mass Spectrometry ◽  
Thermal Decomposition ◽  
Thermogravimetric Analysis ◽  
Metal Atom ◽  
Bond Energies ◽  
Partial Decomposition ◽  
Temperature Range ◽  
Long Period

ABSTRACTDecomposition of Sr(tmhd)2 and Ba(tmhd)2 was investigated by thermogravimetric analysis, in-situ FTIR, and mass spectrometry. Both compounds decomposed following 3 steps: 1) decomposition of the ligands, 2) simultaneous vaporization and partial decomposition of metal-organics, and 3) decomposition of the vaporized metal-organics which existed as the oligomeric species.The Sr source decomposed at lower temperatures and in a narrower temperature range than the Ba source. Also, the gaseous oligomeric species from the Sr source decomposed relatively quickly while the corresponding species from the Ba source decomposed slowly over a long period. Such a difference between the two compounds is due to different bond energies between the metal atom and the ligands, as indicated by our FTIR results.

Mechanical Properties of WC-Co Cemented Carbide Prepared via Vacuum Sintering

2013 ◽  
Vol 275-277 ◽  
pp. 1917-1920
Author(s):  
Bing Liang Liang ◽  
Yun Long Ai ◽  
Chang Hong Liu ◽  
Nan Jiang
Keyword(s):  
Mechanical Properties ◽  
Phase Composition ◽  
Relative Density ◽  
Sintering Temperature ◽  
Rupture Strength ◽  
Cemented Carbide ◽  
Vacuum Sintering ◽  
Transverse Rupture Strength ◽  
Temperature Range ◽  
Peak Value

WC-Co cemented carbide specimens were prepared via vacuum sintering. The influences of composition and sintering temperature on phase composition, microstructure and mechanical properties of WC-Co cemented carbide were investigated. The results show that dense specimens were obtained in the sintering temperature range of 1280~1400°C and the relative density reached over 95%. Only WC and Co3W3C (-phase) were detected by XRD without any else phases, even though Co. With the ascended sintering temperature, hardness increased and the transverse rupture strength (TRS) ascended to peak value and then descended. WC-Co cemented carbide with excellent mechanical properties (HRA>90, TRS~700MPa and KIC>10MPa•m1/2) were obtained.

Thermal Degradation of Aged Chloroprene Rubber Studied by Thermogravimetric Analysis

2001 ◽  
Vol 74 (4) ◽  
pp. 622-629 ◽  
Author(s):  
Elton L. G. Denardin ◽  
Dimitrios Samios ◽  
Paulo R. Janissek ◽  
Gabriel P. de Souza
Keyword(s):  
Thermogravimetric Analysis ◽  
Thermal Degradation ◽  
Mass Loss ◽  
Activation Energies ◽  
Half Width ◽  
Temperature Elevation ◽  
Kinetic Methods ◽  
Degradation Processes ◽  
Chloroprene Rubber ◽  
Differential Thermogravimetric Analysis

Abstract The thermal degradation of original and aged chloroprene rubber was studied using thermogravimetric analysis. Thermogravimetric analysis (TGA) and differential thermogravimetric analysis (DTG) techniques were used to detect the mass loss during the temperature elevation. By the analysis of the mass loss curves through usual kinetic methods, it was possible to evaluate the different degradation processes present in the overall degradation. The activation energies of the degradation processes were obtained using the dynamic, non-isothermal Kissinger and Osawa methods and the half-width at half-high technique (HWHH). The results obtained demonstrate clearly the differences between original and aged chloroprene rubber as well as the influence of the air and N2 in TGA.

Volatility studies of metal chelates. I. Thermal studies of vanadium β-diketonates

1976 ◽  
Vol 29 (11) ◽  
pp. 2369 ◽  
Author(s):  
S Dilli ◽  
E Patsalides
Keyword(s):  
Thermogravimetric Analysis ◽  
Chemical Stability ◽  
Thermal Studies ◽  
Metal Chelates ◽  
Temperature Range ◽  
Water Saturated ◽  
Thermal And Chemical Stability

The complexes of vanadium(111) and oxovanadium(1V) with pentane-2,4-dione; l,l,l-trifluoropentane-2,4-dione; 1,1,1,5,5,5-hexafluoropentane-2,4-dione; l,l,l-trifluoro-5-methylhexane-2,4-dione; l,l,l-trifluoro-5,5-dimethylhexane-2,4-dine 1,1,1,2,2-pentafluoro-6,6-dimethylheptane-3,5-dione and 1,1,1,2,2,3,3-heptafluoro-7,7-dimethyloctane-4,6-dione have been prepared. The volatility, thermal and chemical stability of the chelates have been examined by simultaneous differential thermal and thermogravimetric analysis in dynamic atmospheres of nitrogen, air and water-saturated nitrogen and air, in addition to heating under vacuum to temperatures approaching 360�C. The vanadium(111) chelates of the fluorinated β-diketones volatilized with little evidence of decomposition even in air and were stable in the absence of air to 280-320�C. In contrast, the oxovanadium(1V)chelates partly decomposed during volatilization at temperatures as low as 150�C, and completelydecomposed over the temperature range 180-240�C.

scholarly journals Thermodynamic studies in the MgO – FeO – Al2O3 system

2020 ◽  
Vol 120 ◽  
pp. 115-119
Author(s):  
O. M. Borysenko ◽  
S. M. Logvinkov ◽  
G. M. Shabanova ◽  
A. M. Korohodska ◽  
I. A. Ostapenko ◽  
...  
Keyword(s):  
Phase Composition ◽  
Thermodynamic Stability ◽  
High Performance ◽  
Binary Systems ◽  
Complete Information ◽  
Phase Changes ◽  
Performance Characteristics ◽  
Refractory Materials ◽  
Component System ◽  
Thermodynamic Studies

Prediction of the phase composition is one of the most important tasks in the development of new refractory materials and their operation in thermal units. The most complete information on phase interactions and thermodynamic stability of phase combinations is contained in the phase diagrams. The article presents thermodynamic studies of the three - component system MgO – FeO – Al2O3, which is of great interest for the production of refractory materials with high performance characteristics. Based on the analysis of binary systems of this system, it was found that, the stable phases are MgO, FeO, Al2O3 and MgAl2O4, FeAl2O4. The results analysis of calculating the Gibbs energy for the reaction (FeO + MgAl2O4 = MgO + FeAl2O4) indicates the thermodynamic stability of the phases combination of MgO, FeAl2O4 to a temperature of 1141 K. Above the temperature of 1141 K FeO and MgAl2O4 are stable phases. Thus, in the system MgO – FeO – Al2O3 up to the temperature of 1141 K, the phases MgO – FeAl2O4 and MgAl2O4 – FeAl2O4 coexist, above this temperature — FeO – MgAl2O4 and MgAl2O4 – FeAl2O4. The data obtained make it possible to predict thermally stimulated phase changes that give the effect of thermoplasticity and will be important for obtaining refractory materials with high performance characteristics based on the MgO — FeO — Al2O3 system.

Sign in / Sign up

Export Citation Format

Share Document