Showing papers in "Journal of Energetic Materials in 1983"
TL;DR: In this article, a large deuterium kinetic isotope effect in the thermal decomposition of methyl deuterated 2,4,6-trini-trotoluene (TNT-α-d3) has been confirmed and tested for its possible influence on the shock sensitivity and detonation velocity.
Abstract: A large deuterium kinetic isotope effect in the thermal decomposition of methyl deuterated 2,4,6-trini-trotoluene (TNT-α-d3) has been confirmed and tested for its possible influence on the shock sensitivity and detonation velocity. A comparison of the exploding foil shock sensitivity tests and miniature detonation velocity measurements performed on TNT-α-d3 and two differently prepared control samples of unlabeled TNT showed that the former was significantly lower in sensitivity as well as detonation velocity. These results indicate that the rate-determining steps in the controlled condensed phase decomposition and in the chemical mechanism of initiation and detonation are likely to be the same.
32 citations
TL;DR: In this paper, it was found that both the ammonium salt of 5-nitrotetrazole (ANT) and the ethylenediamine (ENT) form eutectics with ammonium nitrate (AN).
Abstract: We have found that both the ammonium salt of 5-nitrotetrazole (ANT) and the ethylenediamine salt of 5-nitrotetrazole (ENT) form eutectics with ammonium nitrate (AN). Initial characterization and small-scale sensitivity tests of CO2-balanced AN/ANT and AN/ENT formulations were performed; it was found that both eutectics were less sensitive in all tests than pure ANT or ENT, respectively. The phase diagrams of both mixtures were also determined. ANT forms a eutectic with AN that melts at 121°C; the eutectic composition of the AN/ANT system is 78.5 mol% AN. The eutectic temperature and composition of the AN/ENT system were found to be 110.5°C and 87.8 mol% AN, respectively. Thermal stability studies of the eutectics indicate that they are stable below 160°C and that thermal decomposition occurs slowly over a long period of time. The detonation velocities of both eutectics, measured unconfined at 2.54-cm diameter, were found to be within 95% of those predicted by the Kamlet-Jacobs method assuming ide...
20 citations
TL;DR: In this article, the ignition and growth model of the reactive flow during shock initiation and detonation wave propagation in the heterogeneous solid explosives PBX-9404 and LX-17 is compared to recent embedded particle velocity and stress gauge measurements in detonating PBX 9404 and Fabry-Perot free surface velocity measurements of thin metal plates accelerated by detonating PFs.
Abstract: The ignition and growth model of the reactive flow during shock initiation and detonation wave propagation in the heterogeneous solid explosives PBX-9404 and LX-17 is compared to recent embedded particle velocity and stress gauge measurements in detonating PBX-9404 and Fabry-Perot free surface velocity measurements of thin metal plates accelerated by detonating PBX-9404 and LX-17. The overall agreement between the numerical calculations and the various experimental records, which have time resolutions in the nanosecond regime, is very good. The regions of disagreement emphasize some of the processes involved in reactive flow and metal acceleration that are not fully understood and directions for future experimental and modeling work. These new experimental and calculational results are also compared to some previously reported back surface particle velocity gauge and free surface velocity measurements for detonating PBX-9404. The experimental records and the numerical results clearly demonstrate ...
18 citations
TL;DR: In this article, a comparison between published data for Hugoniot curves generated from shock-wave experiments and isothermal static compression measurements to 10 GPa was made for the four explosives, PETN, RDX, HMX, and TATB.
Abstract: For the four explosives, PETN, RDX, HMX, and TATB, comparison is made between published data for Hugoniot curves generated from shock-wave experiments and Hugoniot curves generated from isothermal static compression measurements to 10 GPa. For PETN, the static and shock Hugoniot curves in the pressure-volume plane are in agreement. From this agreement, one can conclude that the shock data for PETN determine the Hugoniot curve for unreacted material. The same conclusion can be drawn for RDX, although there is a phase transition between 4 and 5 GPa. Also for TATB the two types of data agree over their common range (0 to 7 GPa). For HMX the comparison is not as conclusive, but may indicate the presence of a phase transition in HMX above 10 GPa.
16 citations
TL;DR: In this article, the authors used the two-dimensional Eulerian hydrodynamic code 2DE with the shock initiation of heterogeneous explosive burn model called Forest Fire to model numerically the interaction of jets of steel, copper, tantalum, aluminum, and water with steel, water, and explosive targets.
Abstract: The two-dimensional Eulerian hydrodynamic code 2DE with the shock initiation of heterogeneous explosive burn model called Forest Fire, is used to model numerically the interaction of jets of steel, copper, tantalum, aluminum, and water with steel, water, and explosive targets. The calculated and experimental critical condition for propagating detonation may be described by the Held V/sup 2/d expression (jet velocity squared times the jet diameter). In PBX 9502, jets initiate an overdriven detonation smaller than the critical diameter, which either fails or enlarges to greater than the critical diameter while the overdriven detonation decays to the C-J state. In PBX 9404, the jet initiates a detonation that propagates only if it is maintained by the jet for an interval sufficient to establish a stable curved detonation front. The calculated penetration velocities into explosives, initiated by a low-velocity jet, are significantly less than for non-reactive solids of the same density. The detonation products near the jet tip have a pressure higher than that of nonreactive explosives, and thus slow the jet penetration. At high jet velocities, the calculated penetration velocities are similar for reactive and inert targets. 8 references, 17 figures, 1 table.
15 citations
TL;DR: In this paper, the reactive three-dimensional hydrodynamic code 3DE has been used to investigate the reactive hydrodynamics of a matrix of tungsten particles in HMX.
Abstract: The reactive three-dimensional hydrodynamic code 3DE has been used to investigate the reactive hydrodynamics of a matrix of tungsten particles in HMX. A propagating detonation proceeding through the matrix of tungsten particles gives calculated detonation velocities and pressures that are much higher than observed. If the heterogeneous shock initiation Forest Fire rate for HMX is used to describe the reactive kinetics, some of the individual detonation wavelets between the tungsten particles fail. The shocked explosive continues to decompose and release energy after shock passage. Equations of state are described for a tungsten and a leadloaded explosive that reproduce the observed performance of these nonideal explosives. The calibrated equations of state use a partial energy release suggested by the three-dimensional model. Evidence is presented that the explosives have a flat top Taylor wave characteristic of weak detonations.
11 citations
TL;DR: In this article, reverse phase high performance liquid chromatographic methods have been developed for determining the stabilizer content in a nitrate ester plasticized gas generator propellant, and the accuracy and precision of these methods are demonstrated by the results of stabilizer depletion rate determinations obtained over a three month accelerated aging period.
Abstract: Reverse phase high performance liquid chromatographic methods have been developed for determining the stabilizer content in a nitrate ester plasticized gas generator propellant. The accuracy and precision of these methods are demonstrated by the results of stabilizer depletion rate determinations obtained over a three month accelerated aging period. The stabilizers investigated included diphenylamine (DPA), 2-nitrodiphenylamine (2-NDPA), 4-nitrodiphenylamine (4-NDPA), resorcinol and ethyl centralite (EC). Details of the analytical technique and methods development will be discussed.
9 citations
TL;DR: In this article, a high pressure liquid chromatography method has been developed for rapid and quantitative chemical analysis of the following thermally stable explosive materials: DATB, DINA, DIPAM, DNT, DODECA, HNAB, HNBiB, HMX, HnBP, HNS, NONA, ONT, PA, PETN, PYX, RDX, TATB and TPT.
Abstract: A high pressure liquid chromatography method has been developed for rapid and quantitative chemical analysis of the following thermally stable explosive materials: DATB, DINA, DIPAM, DNT, DODECA, HNAB, HNBiB, HMX, HNBP, HNS, NONA, ONT, PA, PETN, PYX, RDX, TATB, TETRYL, TNA, TNB, TNN, TNS, TNT, and TPT (see glossary). Additional characterization data was obtained using nuclear magnetic resonance spectroscopy, and thin layer chromatography. Melting point data is also reported.
8 citations
TL;DR: In this paper, the free radical produced from solid RDX undergoing thermal decomposition can also be produced in RDX-sulfolane solutions under milder conditions, an earlier free radical is produced which is identified as the known nitroxide.
Abstract: We have observed that the free radical produced from solid RDX undergoing thermal decomposition can also be produced in RDX-sulfolane solutions. Under milder conditions, an earlier free radical is produced which is identified as the known nitroxide. Pronounced radical-cage effects are observed.
8 citations
TL;DR: In this article, the Shipp hexanitrostilbene (HNS) reaction was used to identify the products formed during the HNS process, including trinitrotoluene, trinitrobenzene and trichloronitromethane (chloropicrin).
Abstract: This report describes the separation, characterization, and analysis of products formed during the Shipp hexanitrostilbene (HNS) process. In this process, trinitrotoluene (TNT), dissolved in a mixture of tetrahydrofuran (THF) and methanol (MeOH), reacts with commercial bleach (NaOCl) to form HNS. The identified products include: hexanitrostilbene (HNS), hexanitrobibenzyl (HNBiB), trinitrobenzene (TNB), trinitrobenzoic acid (PiCOOH), trinitrobenzaldehyde (PiCHO), trinitrobenzyl chloride (PiCH2Cl), picryl chloride (PiCl), picric acid (PiOH), trinitrobenzyl alcohol (PiCH2OH), 4,6-dinitro [2,1] benzisoxazole (Anil), and trichloronitromethane (chloropicrin) as well as unreacted TNT. An additional study was made of the PiCH2Cl → HNS reaction which was the source of the red tar components. Approximately 5–10% of the red tar fraction could not be identified. Solvent effects on the yield of several of the above cited by-products are also discussed.
6 citations
TL;DR: In this paper, the physical structure of TNT breaks up during burning in the closed bomb, and the size, shape, and number of fragments are determined by the crystal pattern permitted to develop during the casting procedure.
Abstract: This work shows that the physical structure of TNT breaks up during burning in the closed bomb. Combustion proceeds on fragments with a new surface-to-volume ratio. The size, shape, and number of fragments is determined by the crystal pattern permitted to develop during the casting procedure. The intrinsic burning rate of TNT is very slow in relation to the rate of structural dissociation. Wax, the desensitizing agent used with TNT in the formulation Composition B, does not interact with TNT to modify its burning behavior. The size, shape, and number of fragments is determined by the crystal pattern permitted to develop during the casting procedure. The intrinsic burning rate of TNT is very slow in relation to the rate of structural dissociation. Wax, the desensitizing agent used with TNT in the formulation Composition B, does not interact with TNT to modify its burning behavior.
TL;DR: In this article, shock polarization data was presented for water with both dural and copper working electrodes from 20 kbar (2 GPa) to 100 kbar, and it was concluded for low enough pre-shock electrical conductivity water, that one can neglect electrochemical (electrode material) effects below 50 kbar allowing molecular modeling based upon shock polarization.
Abstract: Shock polarization data is presented for water with both dural and copper working electrodes from 20 kbar (2 GPa) to 100 kbar. It is concluded for low enough pre-shock electrical conductivity water, that one can neglect electrochemical (electrode material) effects below 50 kbar allowing molecular modeling based upon shock polarization data.
TL;DR: Tris(polynitroalkoxy)chloromethanes (chloroorthoformates), a new class of compounds, are prepared by the chlorination of trismethyl disulfides as discussed by the authors.
Abstract: Tris(polynitroalkoxy)chloromethanes (chloroorthoformates), a new class of compounds, are prepared by the chlorination of tris(polynitroalkoxy)methyl disulfides. The chloroorthoformates are reactive intermediates, which with alcohols give mixed 1:3 and 1:1:2 orthocarbonates. Additional derivatives are obtained with nucleophiles such as F−, N3 −, CN−, and 2-imidazolidone.
TL;DR: The feasibility of radiation curing energetic compositions has been demonstrated as discussed by the authors using x-rays at a dose of 1.2 × 106 roentgen to give flexible, rubbery solid materials with rupture stress of 0.8 to 8.3 MPa and strain of 130-230 percent at 25°C.
Abstract: The feasibility of radiation curing energetic compositions has been demonstrated. Binders consisting of vinyl-terminated polybutadieneacrylonitrile copolymer (VTBN) and a combination of styrene and 2-hydroxyethyl methacrylate have been cured using x-rays at a dose of 1.2 × 106 roentgen to give flexible, rubbery solid materials with rupture stress of 0.8 to 8.3 MPa and strain of 130–230 percent at 25°C. Irradiation of RDX (1,3,5-trinitro-l,3,5-triazacyclohexane) and HMX (1,3,5,7-tetranitro-l,3,5,7-tetrazacyclooctane) a t the 1.2 × 106 roentgen dose level caused no measurable ni tramine decomposition. The VTBN binder system loaded with 70% nitramine energetic filler was cured by irradiation (1.2 × 106 roentgen) t o give rubbery solids with 2.2–2.8 MPa stress a t rupture and nearly 100% strain (25°C). The filled systems display Taliani slopes, nitramine phase transitions and decomposition temperatures which are well within normal 1imits for explosives and propellants.
TL;DR: In this article, a theoretical treatment for steady-state planar detonation waves in composite explosives such as Amatex 20 was formulated, which provides a more definitve and realistic description of detonation in such explosives, and extends the classical Zeldovich-von Neumann-Doering model of ideal detonation into a propotype model for nonideal detonation.
Abstract: A theoretical treatment is formulated for steady-state planar detonation waves in composite explosives such as Amatex 20. This treatment provides a more definitve and realistic description of detonation in such explosives, and extends the classical Zeldovich-von Neumann-Doering model of ideal detonation into a propotype model for nonideal detonation. Incomplete decomposition of the slowest reacting component, and incomplete attainment of chemical equilibrium among the detonation products from the different explosive components were assumed to be the kinetic processes responsible for nonideal behavior. The constitutive relationship for the shocked reacting explosive was constructed with different equations of state for the explosives and their products and enough reaction coordinates to account for this type of nonideality. Detonation parameters and Lagrange particle velocity histories were calculated for nonideal detonation waves in an explosive modeling Amatex 20.