Recent Advances in the Thermal Decomposition of Cyclic Nitramines

1992 ◽  
Vol 296 ◽  
Author(s):  
Richard Behrens ◽  
Suryanarayana Bulusu
Keyword(s):  
Thermal Decomposition ◽  
Liquid Phase ◽  
Molecular Conformation ◽  
Reaction Pathways ◽  
Thermally Stable ◽  
Decomposition Products ◽  
Stable Product ◽  
Cyclic Nitramines ◽  
Decomposition Pathway ◽  
Kinetics Of

AbstractThe effects of physical properties and molecular conformation on the thermal decomposition kinetics of several cyclic nitramines are examined and compared to the decomposition of RDX. The compounds used in the study are: octahydro-1,3,5,7-tetranitro- 1,3,5,7-tetrazocine (HMX), hexahydro-l-nitroso-3,5-dinitro-s-triazine (ONDNTA), 1,3,5- trinitro- 1,3,5-triazacycloheptane (TNCHP), and 2-oxo-1,3,5-trinitro-1,3,5-triazacyclohexane (K6). The decomposition pathways of HMX in the liquid phase are similar to the four parallel decomposition pathways that control the decomposition of RDX in the liquid phase. The products formed during the thermal decomposition of ONDNTA arise from multiple reaction pathways. The identities and temporal behaviors of the ONDNTA decomposition products are discussed. TNCHP is thermally stable in the liquid phase. The decomposition products from TNCHP are formed via multiple reaction pathways. One decomposition pathway for TNCHP is through its mononitroso intermediate. TNCHP does not form a stable product that is analogous to oxy-s-triazine (OST) formed in RDX or the smaller ring fragments formed in the liquid-phase decomposition of HMX. K6 is less thermally stable and the decomposition mechanism is much simpler than that of RDX, HMX and TNCHP. The thermal decomposition of K6 occurs between 150 and 180 °C. The products formed during the decomposition of K6 are mainly CH2O and N2O with minor amounts or HCN, CO, NO, and NO2.

The Reactivity of Different Active Forms of Sodium Carbonate with Respect to Sulfur Dioxide

1992 ◽  
Vol 57 (11) ◽  
pp. 2302-2308
Author(s):  
Karel Mocek ◽  
Erich Lippert ◽  
Emerich Erdös
Keyword(s):  
Thermal Decomposition ◽  
Liquid Phase ◽  
Sulfur Dioxide ◽  
Specific Surface ◽  
Surface Area ◽  
Sodium Carbonate ◽  
Room Temperature ◽  
Active Form ◽  
The Other ◽  
Kinetics Of

The kinetics of the reaction of solid sodium carbonate with sulfur dioxide depends on the microstructure of the solid, which in turn is affected by the way and conditions of its preparation. The active form, analogous to that obtained by thermal decomposition of NaHCO3, emerges from the dehydration of Na2CO3 . 10 H2O in a vacuum or its weathering in air at room temperature. The two active forms are porous and have approximately the same specific surface area. Partial hydration of the active Na2CO3 in air at room temperature followed by thermal dehydration does not bring about a significant decrease in reactivity. On the other hand, if the preparation of anhydrous Na2CO3 involves, partly or completely, the liquid phase, the reactivity of the product is substantially lower.

The thermal decomposition of RDX at temperatures below the melting point. I. Comments on the mechanism

1970 ◽  
Vol 23 (4) ◽  
pp. 737 ◽  
Author(s):  
JJ Batten ◽  
DC Murdie
Keyword(s):  
Thermal Decomposition ◽  
Melting Point ◽  
Liquid Phase ◽  
Condensed Phase ◽  
Initial Rate ◽  
Decomposition Products ◽  
Sample Geometry

Two mechanisms have recently been proposed to explain the behaviour of the initial rate of decomposition of RDX, with change in sample geometry. These are (i)that the decomposition proceeds by concurrent gas and liquid phase reactions, and (ii) that gaseous decomposition products influence the rate of decomposition of undecomposed RDX in the condensed phase. In this paper it is concluded that mechanism (ii) is the more probable when the reaction is carried out in the presence of nitrogen.

scholarly journals A Case Study of Polyetheretherketone (II): Playing with Oxygen Concentration and Modeling Thermal Decomposition of a High-Performance Material

Polymers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1577
Author(s):  
Aditya Ramgobin ◽  
Gaëlle Fontaine ◽  
Serge Bourbigot
Keyword(s):  
Thermal Decomposition ◽  
Kinetic Model ◽  
High Performance ◽  
Chain Scission ◽  
Kinetic Decomposition ◽  
Decomposition Models ◽  
Set Up ◽  
Decomposition Pathway ◽  
Kinetics Of

Kinetic decomposition models for the thermal decomposition of a high-performance polymeric material (polyetheretherketone, PEEK) were determined from specific techniques. Experimental data from thermogravimetric analysis (TGA) and previously elucidated decomposition mechanisms were combined with a numerical simulating tool to establish a comprehensive kinetic model for the decomposition of PEEK under three atmospheres: nitrogen, 2% oxygen, and synthetic air. Multistepped kinetic models with subsequent and competitive reactions were established by taking into consideration the different types of reactions that may occur during the thermal decomposition of the material (chain scission, thermo-oxidation, char formation). The decomposition products and decomposition mechanism of PEEK which were established in our previous report allowed for the elucidation of the kinetic decomposition models. A three-stepped kinetic thermal decomposition pathway was a good fit to model the thermal decomposition of PEEK under nitrogen. The kinetic model involved an autocatalytic type of reaction followed by competitive and successive nth order reactions. Such types of models were set up for the evaluation of the kinetics of the thermal decomposition of PEEK under 2% oxygen and in air, leading to models with satisfactory fidelity.

Thermal decomposition studies of highly alternating CO2- cyclohexene oxide copolymer

e-Polymers ◽  
2009 ◽  
Vol 9 (1) ◽  
Author(s):  
Luo Jianxin ◽  
Zhang Min ◽  
Zou Zhiqiang ◽  
Liu Baohua ◽  
Chen Liban
Keyword(s):  
Thermal Decomposition ◽  
Kinetic Method ◽  
Carbonate Content ◽  
Cyclohexene Oxide ◽  
Decomposition Products ◽  
Tg Analysis ◽  
H Nmr ◽  
Nmr Techniques ◽  
Using Data ◽  
Kinetics Of

AbstractHighly alternating CO2-cyclohexene oxide copolymer, namely poly(cyclohexene carbonate) (PCHC), considered potentially to be microelectronic sacrificial material, was successfully synthesized by copolymerization of cyclohexene oxide and CO2 in the presence of SalenAl(OiPr) catalyst. The obtained highly alternating PCHC copolymer were determined and proven to have superior thermal decomposition properties decomposing completely at 350 oC by thermogravimetric (TG) analysis under dynamic conditions. The thermal decomposition kinetics of the obtained PCHC was investigated by a different kinetic method using data from TG analysis. Based on the analytical, kinetic parameters were calculated and kinetic model of pyrolysis was proposed. TG-IR, Py-GC/MS, IR and 1H NMR techniques were applied to investigate the decomposition process. Based on Py-GC/MS and TG-IR techniques, carbon dioxide, 1,3-cyclohexadiene, cyclopentanecarboxaldehyde, cyclohexene oxide, cyclohexanone and trans-1,2- carbonyldioxycyclohexane were identified as thermal decomposition products of PCHC. The solid residues of the PCHC with 25% ether linkages decomposed at 200, 250, 300, 350 oC as determined by IR and 1H NMR. The results demonstrated that the carbonate content of the solid residues decreased gradually at elevated heat-temperatures and at 350 oC only few polyether linkages were observed.

THERMAL DECOMPOSITION AND DESORPTION OF DIETHYLAMIDO OF TETRAKIS(DIETHYLAMIDO)ZIRCONIUM (TDEAZr) ON Si(100)

2003 ◽  
Vol 10 (01) ◽  
pp. 121-125 ◽  
Author(s):  
JOONHEE JEONG ◽  
SUNGWON LIM ◽  
KIJUNG YONG
Keyword(s):  
Thermal Decomposition ◽  
Photoelectron Spectroscopy ◽  
Film Growth ◽  
Reaction Pathway ◽  
Thin Film Growth ◽  
Decomposition Products ◽  
Main Decomposition ◽  
Temperature Programmed ◽  
N Incorporation ◽  
Decomposition Pathway

The thermal decomposition pathway and desorption of diethylamido of tetrakis(diethylamido)zirconium [TDEAZr, Zr(N(C2H5)2)4] on Si(100) were studied using temperature-programmed desorption (TPD) and X-ray photoelectron spectroscopy (XPS). During TPD experiments, ethylethyleneimine (C2H5N=CHCH3), diethylamine [NH(C2H5)2], acetonitrile (CH3CN), ethylene (C2H4) and hydrogen (H2) desorbed as the main decomposition products of diethylamido, which was chemisorbed on Si(100) through the scission of the zirconium–diethylamido bond in TDEAZr. After TPD runs, the formation of silicon carbide and silicon nitride was observed on the surface by XPS, indicating that a complete decomposition of diethylamido proceeded. This could be a reaction pathway of C, N incorporation in the thin film growth using TDEAZr as a Zr precursor.

Thermal decomposition of diazirines in the presence of m-chloroperoxybenzoic acid. A method to determine the partitioning of reaction pathways

1979 ◽  
Vol 57 (11) ◽  
pp. 1299-1303 ◽  
Author(s):  
Michael T. H. Liu ◽  
Iwao Yamamoto
Keyword(s):  
Thermal Decomposition ◽  
Activation Parameters ◽  
Kinetic Studies ◽  
Oxidation Products ◽  
Reaction Pathways ◽  
Decomposition Products

The oxidation of various diazirines by m-chloroperoxybenzoic acid as well as the activation parameters for these reactions have been investigated. The oxidation products and the information derived from kinetic studies indicate that the oxidation does not take place on the diazirine ring as expected but rather on the decomposition products of the diazirines. The oxidation products obtained are shown to be characteristic of the diazirine decomposition by carbenic and diazo pathways and thus the measurement of the oxidation products provides a measure of the partitioning of the two reaction pathways for diazirine decomposition.

scholarly journals STUDIES ON THE PERVANADIUM COMPLEX

1961 ◽  
Vol 39 (6) ◽  
pp. 1174-1183 ◽  
Author(s):  
G. A. Dean
Keyword(s):  
Activation Energy ◽  
Thermal Decomposition ◽  
Acid Solution ◽  
Anionic Complex ◽  
Cationic Complex ◽  
Kcal Mole ◽  
Decomposition Products ◽  
First Order ◽  
Discrete Variations ◽  
Kinetics Of

The 'pervanadium complex' is investigated in a general manner. The kinetics of its thermal decomposition in acid solution are shown to be first order with respect to pervanadium, the apparent activation energy is 26.5 ± 1.0 kcal/mole, and possible mechanisms are suggested. The effect of various acids upon the nature of the decomposition products is determined: almost quantitative yields of vanadium (V) or vanadium (IV) are obtained in very dilute or concentrated acid, respectively. Spectrophotometric studies indicate that in acid solution two separate complexes exist: a red (1:1) cationic complex and a yellow (1:2) anionic complex. The stoichiometry of the equilibrium between the two complexes in solutions of sulphuric acid is investigated by a method of 'discrete variations'. The equilibrium could be described by[Formula: see text]where Kr/y = 2.2 ± 0.2 at 22 °C. The anion is shown to play an important part in determining the nature of the pervanadium complex.

Sign in / Sign up

Export Citation Format

Share Document