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

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.

1970 ◽  
Vol 23 (4) ◽  
pp. 749 ◽  
Author(s):  
JJ Batten ◽  
DC Murdie

The activation energy has been determined in the temperature range 170-198�. If the sample was spread the activation energy was independent of the definition of the kinetic parameter substituted in the Arrhenius equation and was 63 kcal mole-1. In the case of the unspread samples the activation energies of the induction, acceleration, and maximum rates were 49, 43, and 62 kcal mole-1 respectively. The effect that sample geometry has on the activation energy is attributed to gaseous decomposition products influencing the reaction.


1995 ◽  
Vol 418 ◽  
Author(s):  
David J. Beardall ◽  
Tod R. Botcher ◽  
Charles A. Wight

AbstractThe initial step of the thermal decomposition of NTO (5-nitro-2,4-dihydro-3H-1,2,4- triazol-3-one) is determined by pulsed infrared laser pyrolysis of thin films. Rapid heating of the film and quenching to 77 K allows one to trap the initial decomposition products in the condensed phase and analyze them using transmission Fourier-transform infrared spectroscopy. The initial decomposition product is CO2; NO2 and HONO are not observed. We propose a new mechanism for NTO decomposition in which CO2 is formed.


1971 ◽  
Vol 24 (5) ◽  
pp. 945 ◽  
Author(s):  
JJ Batten

The rate of thermal decomposition of RDX has been investigated in the presence of its decomposition products and free radical traps. From the measurements, it is concluded that formaldehyde and nitrogen dioxide, presumably ?encaged? in the sample, catalyse the decomposition of RDX positively and negatively respectively. The non-volatile residue also acts as a positive catalyst. The other products have little or no effect on the rate, and the free radical traps did not reduce the rate.


1992 ◽  
Vol 296 ◽  
Author(s):  
Richard Behrens ◽  
Suryanarayana Bulusu

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.


1995 ◽  
Vol 418 ◽  
Author(s):  
J. C. Oxley ◽  
J. L. Smith ◽  
K. E. Yeager ◽  
E. Rogers ◽  
X. X. Dong

AbstractTo examine the thermal decomposition of 5-nitro-2,4-dihydro-3H-1,2,4-triazol-3-one (NTO) in detail, isotopic labeling studies were undertaken. NTO samples labeled with 15N in three different locations [ N(l) and N(2), N(4), and N (6)] were prepared.1 Upon thermolysis, the majority of the NTO condensed-phase product was a brown, insoluble residue, but small quantities of 2,4,-dihydro-3H- 1,2,4-triazol-3-one (TO) and triazole were detected.2 Gases comprised the remainder of the NTO decomposition products. The analysis of these gases is reported herein along with mechanistic implications of these observations.


1992 ◽  
Vol 57 (11) ◽  
pp. 2302-2308
Author(s):  
Karel Mocek ◽  
Erich Lippert ◽  
Emerich Erdös

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.


2014 ◽  
Vol 13 (04) ◽  
pp. 1450022 ◽  
Author(s):  
Zerong Daniel Wang ◽  
Meagan Hysmith ◽  
Perla Cristina Quintana

The formation of carbon disulfide ( CS 2) and ammonia ( NH 3) from the thermal decomposition products of thiourea has been studied with MP2, and hybrid module-based density functional theory methods (B3LYP, MPW1PW91 and PBE1PBE), each in conjunction with five different basis sets (6-31+G(2d,2p), 6-311++G(2d,2p), DGDZVP, DGDZVP2 and DGTZVP). The free energy changes and activation energies for all the five primitive reactions involved in the formation of CS 2 and NH 3 have been compared and discussed. The results indicate that CS 2 is most likely formed in a consecutive reaction path that consists of the addition of hydrogen sulfide ( H 2 S ) to isothiocyanic acid (HNCS) to generate carbamodithioic acid and subsequent decomposition of carbamodithioic acid. By contrast, thiocyanic acid (HSCN) as the structural isomer of isothiocyanic acid is not likely the source of CS 2.


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