Study on the stability effect and mechanism of aniline-fullerene stabilizers on nitrocellulose based on the isothermal thermal decomposition

2020 ◽  
Vol 178 ◽  
pp. 109221 ◽  
Author(s):  
Liqiong Luo ◽  
Qiong Huang ◽  
Bo Jin ◽  
Zuohu Chai ◽  
Zhiliang Guo ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
The Stability ◽  
Stability Effect

scholarly journals The influence of the nature and textural properties of different supports on the thermal behavior of Keggin type heteropolyacids

2006 ◽  
Vol 71 (3) ◽  
pp. 235-249 ◽  
Author(s):  
Alexandru Popa ◽  
Viorel Sasca ◽  
Mircea Stefanescu ◽  
Erne Kis ◽  
Radmila Marinkovic-Neducin
Keyword(s):  
Thermal Stability ◽  
Thermal Decomposition ◽  
Thermal Behavior ◽  
Solid Phase ◽  
Textural Properties ◽  
Nitrogen Adsorption ◽  
Active Phase ◽  
Support Surface ◽  
Sem Images ◽  
The Stability

In order to obtain highly dispersed heteropolyacids (HPAs) species, H3PMo12O40 and H4PVMo11O40 were supported on various supports: silica (Aerosil - Degussa and Romsil types) and TiO2. The structure and thermal decomposition of supported and unsupported HPAs were followed by different techniques (TGA-DTA, FTIR, XRD, low temperature nitrogen adsorption, scanning electron microscopy). All the supported HPAs were prepared by impregnation using the incipient wetness technique with a 1:1 mixture of water-ethanol. Samples were prepared with different concentrations to examine the effect of loading on the thermal behavior of the supported acid catalysts. The thermal stability was evaluated with reference to the bulk solid acids and mechanical mixtures. After deposition on silica types supports, an important decrease in thermal stability was observed on the Romsil types and a small decrease on the Aerosil type. The stability of the heteropolyacids supported on titania increased due to an anion-support interaction, as the thermal decomposition proceeded in two steps. The structure of the HPAs was not totally destroyed at 450 ?C as some IR bands were still preserved. A relatively uniform distribution of HPAs on the support surface was observed for all compositions of the active phase. No separate crystallites of solid phase HPAs were found in the SEM images.

Theoretical Study on Thermal Hazardous Properties of C18H10O11 and C18H18O7 Organic Peroxides

2013 ◽  
Vol 787 ◽  
pp. 301-305
Author(s):  
Yun Bo He ◽  
Wei Wang ◽  
Shi Xiong Wang ◽  
Xiang Jun Yang ◽  
Hong Guo
Keyword(s):  
Molecular Structure ◽  
Thermal Decomposition ◽  
Quantum Chemistry ◽  
Organic Compounds ◽  
Theoretical Study ◽  
Organic Peroxides ◽  
Quantum Chemistry Calculation ◽  
The Past ◽  
Chemistry Calculation ◽  
The Stability

The thermal decomposition of organic peroxides are widely used as coagulant for organic compounds, however, its thermal hazardous characteristics have already caused serious accidents in chemical industries, which limited its application in much more strict conditions. Organic peroxides of C18H10O11 and C18H18O7 are two new candidates fitted for industrial explosive. However, as we best known there is little reports available on the geometry structure in the past decades. In this work, by means of quantum chemistry calculation, the relation of safety with molecular structure of C18H10O11 and C18H18O7 are discussed. The molecules with more activity O and the activity part more dispersedly exhibit higher stable, and the configuration has good safety. All the energy of molecule b is higher than that of molecule a. The stability of different configurations are 6a>7a>8a>9a>5a>1a>4a>3a=2a and 1b>7b>5b>6b>4b>2b>3b>8b, respectively, suggesting the structures of 6a,3a,2a,1b,8b exhibit high safety.

Quantitative Control of C2S Crystal Transformation

2011 ◽  
Vol 121-126 ◽  
pp. 311-315
Author(s):  
Ming Zhao
Keyword(s):  
Sintering Temperature ◽  
Cement Clinker ◽  
Crystal Transformation ◽  
Chemical Impurities ◽  
Stabilizer Concentration ◽  
Rate Of Cooling ◽  
The Stability ◽  
Cement Clinkers ◽  
Stability Effect ◽  
Cooling Methods

Crystal transformation of dicalcium silicate (2CaO•SiO2, C2S) has influences on the microstructure, hydraulicity, and grindability of cement clinker. The transformation of β-C2S to γ-C2S can destroy the clinker nodule integrity by volume expansion due to the low density of the γ-phase. It can be used to pulverize cement clinkers for saving grinding energy, but the hydraulicity of γ-C2S is lower than β-C2S. Quantitative control of C2S crystal transformation could balance the energy saving and hydraulicity. The influences of sintering temperatures, cooling methods and chemical impurities on the transformation were investigated. The results show that the appropriate sintering temperature of γ-C2S was 1250～1500 °C, and the rate of cooling should not be higher than 500 °C/min to guarantee β-C2S transform to γ-C2S. Chemical impurities (Na2O, P2O5, B2O3, Cr2O3 and K2O) were stabilizers of β-C2S, which could prevent β-C2S transforming to γ-C2S. The stability effect was related to their concentrations. The characteristic concentrations of Na2O, P2O5, B2O3, Cr2O3 and K2O were approximately 1.2%, 0.3%, 0.3%, 1.0% and 1.5%, respectively. Above these concentrations, most of β-C2S could be stabilized rather than transforming to γ-C2S. In “transition zone”, C2S crystal transformation could be controlled quantitatively by adjusting the stabilizer concentration.

scholarly journals The thermal decomposition of the pyridine saccharinates of Co, Ni and Cu: A correlation of the structural and the infrared data

1999 ◽  
Vol 64 (10) ◽  
pp. 609-620 ◽  
Author(s):  
Pance Naumov ◽  
Gligor Jovanovski ◽  
Vera Jordanovska ◽  
Boyan Boyanov
Keyword(s):  
Thermal Decomposition ◽  
Thermal Behavior ◽  
Ambient Temperature ◽  
Spectral Characteristics ◽  
Structural Data ◽  
Oxidizing Atmosphere ◽  
Air Atmosphere ◽  
Infrared Spectral ◽  
The Stability ◽  
Infrared Data

In order to investigate the differences in the stability of the isomorphous pyridine saccharinates [Co(H2O)4(C5H5N)2](C7H4NO3S)2.4H2O and [Ni(H2O)4(C5H5N)2] (C7H4NO3S)2.4H2O, their thermal behavior (TG, DTG and DTAcurves) from ambient temperature up to 1000 ?C in a static air atmosphere was studied. For comparative purposes, the thermoanalytical curves of [Cu(H2O)(C5H5N)2(C7H4NO3S)2] were recorded as well. The decomposition pathways and the stability of the compounds are interpreted in the terms of the structural data. A possible mechanism for the decomposition of the saccharinato ion/ligand in an oxidizing atmosphere is proposed.The infrared spectral characteristics of the complexes are also discussed.

The thermal decomposition of aromatic compounds - II. Dichlorobenzenes

1954 ◽  
Vol 224 (1159) ◽  
pp. 544-551 ◽  
Keyword(s):  
Thermal Decomposition ◽  
Thermal Stabilities ◽  
Carbonaceous Deposit ◽  
Chain Processes ◽  
Composition And Structure ◽  
Gaseous Decomposition Product ◽  
Molecular Reaction ◽  
Complete Exclusion ◽  
The Stability ◽  
Kinetic Features

A kinetic study of the thermal decomposition of the dichlorobenzenes shows that the three isomers behave similarly. The compounds differ strikingly from chlorobenzene, inasmuch as the rate of decomposition is not reduced by nitric oxide or ammonia. Other kinetic features suggest that the reaction is unimolecular, and that chain processes do not occur to an appreciable extent. The main gaseous decomposition product is hydrogen chloride, and nearly all the combined chlorine can be accounted for as this product. Very small amounts of gaseous hydrogen are also found, but the balance of the combined hydrogen remains in the carbon deposited on the walls of the reaction vessel; this carbonaceous deposit is of similar composition and structure to that formed from chlorobenzene. Comparison of the thermal stabilities of benzene, chlorobenzene and the dichlorobenzenes shows that the stability is dependent on the extent of substitution of the aromatic ring but is little influenced by the relative positions of the substituents. The increased rate of decomposition caused by a second chlorine atom is evidently due to its ability to facilitate a molecular reaction, which apparently operates to the complete exclusion of chain processes.

Spectral, Magnetic and Thermogravimetric Studies of Some Dimeric Oxovanadium(IV) Complexes

1986 ◽  
Vol 41 (11) ◽  
pp. 1443-1446
Author(s):  
P. K. Nath ◽  
N. C. Mishra ◽  
V. Chakravortty ◽  
K. C. Dash
Keyword(s):  
Thermal Decomposition ◽  
Schiff Base ◽  
Ir Spectra ◽  
Magnetic Moment ◽  
Epr Spectroscopy ◽  
Anthranilic Acid ◽  
Room Temperature ◽  
Thermogravimetric Studies ◽  
Epr Signal ◽  
The Stability

Abstract The tridentate dibasic Schiff base anthranilic acid salicylideneimine (H2SB) reacts with VOCl2 in the presence o f NaOAc and imidazole (or its derivatives) to form dimeric oxovanadium (IV) complexes of the type [VO(S B)(D)]2. These green or yellow -green compounds have a magnetic moment of 1.4 B.M . at room temperature, and are non-electrolytes in MeOH . The compounds are characterised on the basis of electronic and IR spectra as well as EPR spectroscopy. The IR spectra shows a strong band due to v(V = O) at 880 cm-1 in addition to the bands of H2SB and imidazole. [VO(SB)(Im)]2 shows a single unresolved EPR signal at g = 1.9715 whereas compounds containing other imidazole derivatives show both a broadening and shifting of the signal. The thermogravimetric measurements indicate the stability of the complexes and their stepwise thermal decomposition.

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