摘要:

AbstractRecently a new explosive, 3‐Nitro‐1,2,4‐triazole‐5‐one (NTO) has attracted interest as possible replacements for or inclusion in various military propellants and explosives. Analysis of NTO compounds as well as 14 other nitramine and nitroaromatic explosives could be accomplished by capillary electrophoresis using a technique known as MECC, micellar electrokinetic capillary chromatography. A borate/boric acid buffer with sodium dodecylsulfate (SDS) was used in conjunction with direct UV detection

ISSN:0721-3115    

DOI:10.1002/prep.19970220102

出版商:WILEY‐VCH Verlag GmbH    

年代:1997

数据来源: WILEY

摘要:

AbstractExperimental facts show that when the direction of a metallic jet is inclined to the target surface, the penetration length may be decreased enormously. In this paper, the author proves this phenomena by a theoretical analysis. The conclusion could also be used in the respect of anti‐hollow charge warhead

ISSN:0721-3115    

DOI:10.1002/prep.19970220103

出版商:WILEY‐VCH Verlag GmbH    

年代:1997

数据来源: WILEY

摘要:

AbstractThe effect of bypass air momentum on the combustion efficiency of a boron‐carbide fueled solid‐fuel ramjet motor has been investigated theoretically. A 3‐D model of the flow in the aft‐burner has been developed and solved numerically. The theoretical results indicated that combustion efficiency can be increased by employing bypass air with low dump momentum, in agreement with experimental results. High bypass air dump momentum was shown to enhance extinguishment of particle combustion through increased collisions with the moto

ISSN:0721-3115    

DOI:10.1002/prep.19970220104

出版商:WILEY‐VCH Verlag GmbH    

年代:1997

数据来源: WILEY

摘要:

AbstractThe degradation kinetics of solid rocket propellant based on a glycidyl azide polymeric binder with ammonium nitrate were determined by gas chromatographic quantitation of the headspace gases over heated samples. This approach was found to allow the determination of degradation at temperatures approaching ambient. An Arrhenius plot was constructed from the data and kinetic parameters, including activation energy and relative rates of degradation, were calculated. Two different batches of propellant were found to exhibit similar degradation kinetics, although one was estimated to have a shorter service life based on the relative volumes of gases liberated.

ISSN:0721-3115    

DOI:10.1002/prep.19970220105

出版商:WILEY‐VCH Verlag GmbH    

年代:1997

数据来源: WILEY

摘要:

AbstractChemical equilibrium calculations are made for a number of Carbon C, Hydrogen H, Nitrogen N, and Oxygen O, explosive compositions. A methodology is established to systematically limit the number of product species available in thermochemical equilibrium calculations. The calculations are then compared with “baseline” results obtained using an extensive product species library consisting of 900 gas‐phase and 600 condensed‐phase product species. Errors in bulk thermodynamic properties (detonation velocity and pressure) and in product chemical composition are quantified in terms of the number of species considered as products of reaction. The properties at states along an expansion isentrope are also pr

ISSN:0721-3115    

DOI:10.1002/prep.19970220106

出版商:WILEY‐VCH Verlag GmbH    

年代:1997

数据来源: WILEY

摘要:

AbstractThe simultaneous thermogravimetric modulated beam mass spectrometry (STMBMS) technique has been applied to measure the vapor pressures and evaluate the thermal decomposition chemistry of two energetic liquids, bis(2‐fluoro‐2,2‐dinitroethyl)formal (FEFO) and bis(2‐fluoro‐2,2‐dinitroethyl)difluoroformal (DFF). The resulting heat of vaporization (ΔHvap) and vapor pressure at 25°C are 20.3 ± 0.2 kcal/mol and 0.4 ± 0.1 millitorr for FEFO, and 17.3 ± 0.2 kcal/mol and 5.1 ± 1.1 millitorr for DFF. The thermal decomposition of FEFO indicates there are six major pyrolysis pathways. The results suggest that FEFO initially decomposes at 150°C by rearrangement of the nitro group (NO2) to the nitrite group (ONO), followed by loss of NO. Some NO2is also formed at 170°C. Between 200°C–300°C, further pyrolysis occurs. In one pathway, the FEFO backbone remains intact and a high molecular‐weight product is formed. The other three pathways involve scission of the FEFO backbone; one yielding CO2(possibly N2O), one yielding CH2O and CO, and one yielding C3H2NOF. Differences in the thermal decomposition behaviors in the liquid and gas phases are observed. In the thermal decomposition of DFF, the formal fluorine atoms stabilize the backbone structure. Numerous minor thermal decomposi

ISSN:0721-3115    

DOI:10.1002/prep.19970220107

出版商:WILEY‐VCH Verlag GmbH    

年代:1997

数据来源: WILEY

摘要:

AbstractThe present work is devoted to the determination of conditions of thermodynamic stability of carbon nitride having structure of β‐C3N4. The thermodynamic functions of crystalline covalent carbon nitride required for thermodynamic reckoning of parameters of formation of carbon nitride were determined on the base of the Debye theory with the characteristic temperature varied in the range from 1000 K to 2500 K. The formation enthalpy of carbon nitride was estimated on the base of the energy of atomization and formation enthalpy of a mixture of atomized carbon and nitrogen. The resulted quantity of the standard formation enthalpy of covalent carbon nitride at 298.15 K made up 4.47 kcal/mol. Thermodynamic computations were accomplished with the use of the Automated System of Thermodynamic Reckonings and Algorithms ASTRAL. Behavior of the gaseous phase of a chemical system was described by the BKW‐RR equation of state. Carbon nitride was considered to be incompressible. The region of thermodynamic stability of covalent carbon nitride is computed. It is shown that in contrast to the carbon condensation into graphite the pressure of condensation of β‐C3N4when adding other chemical elements to a thermodynamic system can not only increase but decrease as well. Consideration of detonation and explosion processes in high explosives shows a way for practical synthesis of covalent carbon

ISSN:0721-3115    

DOI:10.1002/prep.19970220108

出版商:WILEY‐VCH Verlag GmbH    

年代:1997

数据来源: WILEY

摘要:

AbstractKinetic constants for decomposition of nitrocellulose in the 50 °C to 500°C range are analyzed. At T200°C, the kinetics are consistent with the existence of the first‐order step and desorption of the products as two parallel processes which, together, control the rate. Time‐to‐exotherm and mass burning rate kinetics are compared as temperature‐dependent reaction

ISSN:0721-3115    

DOI:10.1002/prep.19970220109

出版商:WILEY‐VCH Verlag GmbH    

年代:1997

数据来源: WILEY

摘要:

AbstractWe constructed a Jones‐Wilkins‐Lee (JWL) equation of state (EOS) for the PBX 9502 detonation products based on a standard one by lowering the Chapman‐Jouguet (CJ) pressure. We found that a slow component exists in the chemical reaction rate, and the global hydrodynamic behavior as exhibited by the standard EOS reflects such an effect. By reducing the CJ pressure, we effectively remove the contribution of the slow reaction from the standard EOS, and the new EOS should represent the detonation products better. In conjunction with a reactive burn model which includes a slow component, the products EOS performs better than the standar

ISSN:0721-3115    

DOI:10.1002/prep.19970220110

出版商:WILEY‐VCH Verlag GmbH    

年代:1997

数据来源: WILEY

摘要:

AbstractThe reactivity of sodium azide, activated sodium azide and hydrazinium azide towards various dioxygenyl salts was studied. Under no circumstances the formation of dioxygenyl azide, O2N3, could be observed. This is in agreement with high level quantumchemical ab initio computations at correlated level (MP2, PMP2, CISD), predicting the decomposition of hypothetical O2+(g)/N3−(g) to be thermodynamically highly favorable (MP2: −326; PMP2: −328; CISD; −369 [kcal/mol]). The combustion of O2BF4with either N2H5N3(spontaneous reaction on contact in a coaxial solid‐propellant system) or NaN3(safe to handle, highly exothermic reaction after ignition) is discussed in terms of high‐energy‐density materials (HEDM).\documentclass{article}\pagestyle{empty}\begin{document}$$ \begin{array}{l} {\rm NaN}_{\rm 3} + {\rm O}_{\rm 2} {\rm BF}_{\rm 4} + 4/3\,{\rm Al} \rightarrow {\rm NaBF}_{\rm 4} + 3/2\,{\rm N}_{\rm 2} + 2/3\,{\rm Al}_{\rm 2} {\rm O}_{\rm 3} \\ \Delta {\rm H = - 434}\,{\rm kcal/mol} \\ \end{array} $$

ISSN:0721-3115    

DOI:10.1002/prep.19970220111

出版商:WILEY‐VCH Verlag GmbH    

年代:1997

数据来源: WILEY