bluuebunny/crossref_metadata_2025_split huggingface dataset:
Combustion of Black Powder. Part 1: Thermo‐analytical studies
Authors: Hussain G. , Rees G. J. 
Published: May 2005

AbstractAn experimental programme is described, in which a number of thermo‐analytical techniques, differential scanning calorimetry (DSC), thermogravimetry (TG and DTG) are applied to investigate the combustion of black powder. The primary aim has been to investigate, and determine qualitatively and quantitatively, the nature of the solid products of combustion. Additionally, standard analytical techniques were applied, to a chemical analysis of the solid products, resulting from the electric arcignition of a sample of black‐powder, under ambient, open air conditions. The solid products formed 33% by weight of the unburned black powder, consisting of K2SO4 (15%), K2CO3 (11.5%) and small amounts of KNO3 and KNO2. The DSC, TG and DTG analyses suggest a mechanism for the combustion, based on phase changes and transition stages of sulfur and KNO3, and their interaction with charcoal.
FTIR spectroscopic study on the Interaction between Ammonium Perchlorate and Bonding Agents
Authors: Hori Keiichi , Iwama A. , Fukuda Takaaki 
Published: May 2005

AbstractThe interaction between ammonium perchlorate and bonding agents has been investigated by means of Fourier transform infrared spectroscopy (FTIR). The analysis results endorse that the interfacial bonding force is hydrogen bond for aziridine type compounds and ionic bond for alkylene polyamine derivatives, respectively.
Detonation Behavior of Emulsion Explosives
Authors: Lee Jaimin , Persson Per‐Anders 
Published: May 2005

AbstractDetonation behavior of emulsion explosives sensitized by glass microballoons was studied. The detonation velocity and the failure diameter of emulsion explosives at various densities were measured in two charge configurations: cylindrical charges by ionization pins and conical charges by ionization pins and continuous resistance probes. The effect of microballoon size on detonation velocity and failure diameter was also determined.The behavior of emulsion explosives showed a marked difference from that of other high explosives; the detonation velocity reached its maximum far below the maximum density; the failure diameter increased with increasing density. The detonation velocity extrapolated to infinite diameter deviated increasingly from the predictions of the BKW code and of the Kamlet method as the initial density decreased. Diameter effect curves were downward concave and the diameter effect became more pronounced with increasing density. The temperature had a negligibie effect on the detonation velocity. At a given density, the detonation velocity increased linearly with decreasing microballoon size. The increase in detonation velocity was obscured at low densities by the increasing weight of glass added. I he failure diameter had a linear relationship with the spacing between microballoons.
Characteristics of Porous Ammonium Perchlorate and propellants containing same
Authors: Chang Fang‐Mo , Huang Chen‐Chia , Yeh Tsao‐Fa , Liu Chao‐Shih , Leu An‐Lu 
Published: May 2005

AbstractPorous ammonium perchlorate (PAP) was prepared by a successfully developed fluidization process at 230°C. The geometric structure of manufactured PAP was characterized by means of a scanning electron microscope (SEM). The physical and mechanical properties of composite propellans containing PAP were also determined. Owing to the diffusion of binder into pores of PAP, the elongation of propellants decreased.
Studies on octahydro‐1,3,5,7‐tetranitro‐1,3,5,7‐tetrazocine (HMX) polymorphism
Authors: Achuthan C. P. , Jose C. I. 
Published: May 2005

AbstractVarious methods of preparation of the different polymorphs of HMX have been evaluated. Infrared and Raman spectra have been used to differentiate the polymorphs and understand their conformational behaviour. Possible conformation of the γ form has been suggested.
Fragment Mass Distribution of “Secondary Fragments”
Authors: Held Manfred 
Published: May 2005

AbstractAn analysis of the secondary fragments emerging from a target plate has shown that their mass distribution fits excellently to a formula established earlier by the author. This applies equally well to the secondary fragments of an explosive‐formed fragment from a multi‐P warhead, to those from the warhead's structural casing. and even to the fragments from the target plate itself, as well as to the sum of all of these 3 types of fragements. The correlation coefficient for the two constant parameters governing this formula (namely, the scaling factor B and the form factor λ) is always better than 0.99, when an optimum total mass Mo is southt and inserted, and when the first, large fragements are not included in the consideration, which means when one or two measured points are negiected. For secondary fragements, the form factor λ in the mass distribution is close to 1/2 = 0.5, whereas for the natural fragments of HE projectiles it is in the order of 2/3. namely, from 0.6 to 0.8.
Predicting the density distribution in pressed charges using the finite element method
Authors: Essig W. , Osswald T. A. , Saßmannshausen U. 
Published: May 2005

AbstractHigh performance shaped charges require a perfect rotational symmetry and material homogenity. In order to obtain the desired geometry of a detonation wave the density distribution of the explosive, inside such a charge, must meet certain specifications and must be symmetric. This paper presents a finite element simulation of the pressing process of shaped charges implementing a recently developed material model. The calculated result agree well analytical solutions and experiments.
Effect of Boron Particle Surface Coating on combustion of solid propellants for ducted rockets
Authors: Liu Tai‐Kang , Luh Song‐Ping , Perng Huey‐Cherng 
Published: May 2005

AbstractCombustion behavior of B/MA/AP/HTPB fuel rich propellants containing different coated boron particles was studied with several diagnostic facilities such as windowed strand burner, CO2 laser ignition facility, rapid depressurization quenched device, thermal analyzer and micromotor static test. Materials selected for boron coating include LiF, Viton A and silane. Baseline propellant containing uncoated boron was also studied for comparison Results from windowed strand burner and static test show that LiF‐propellant exhibits the most remarkable overall behavior. Ignition study indicates that LiF‐propellant gives the shortest while Viton A‐propellant gives the longest ignition time under the same heat flux. Moreover, mechanisms were proposed to elucidate the experimental results and the observed combustion phenomena.
Energetic Solid Fuels for Ducted Rockets (II)
Authors: Kubota N. , Yano Y. , Miyata K. , Kuwahara T. , Mitsuno M. , Nakagawa I. 
Published: May 2005

AbstractThe combustion characteristics of variable‐flow ducted rockets were evaluated in order to obtain optimum design parameters of the gas generators. The energetic solid fuels used for the gas generators were glycidyl azide polymer (GAP) with burning rate catalysts. The burning rate of GAP based energetic fuels was much higher than that of composite and double‐base based fuel‐rich propellants. The pressure exponent of the burning rate was high enough to obtain a wide range of variable‐flow rat. Two types of combustion test were conducted: a semi‐free jet and a direct connect flow. The pressure‐time response in the primary combustor obtained by the use of a throttable nozzle was evaluated.
The energy and pressure exponent of composite modified double‐base propellant
Authors: Zhulin Hou , Zeng‐guo Feng , Enpu Wang , Panming Han 
Published: May 2005

AbstractThe paper describes an analysis on the energy and pressure exponents of composite modified double‐base (CMDB) propellants. The evaluation of the energy was conducted by means of a thermodynami‐ cal program. Propellant burning rates were determined by the strand burner method. In the AP‐based composition, the energy is enhanced and the pressure exponent reduced with increasing AP content. When AP is partially or entirely replaced by the nitramines HMX or RDX, Isp is improved, and the pressure exponent is inevitably increased. A mixture of lead salicylate or lead o‐amino benzoate and copper 2,4‐ or 3,5‐dihydroxy benzoate produces a remarkable effect on the burning nature of the CMDB propellant. It was noted that the pressure exponent decreases from 0.66 to 0.48 with lead and copper salts added at 3.0% in AP‐Al, 0.82 to 0.60 at 2.0% in RDX‐Al and 0.72 to 0.54 at 2.5% in RDX‐AP‐Al compositions, respectively.
Thermal decomposition of energetic materials. 55. Metal Complexes of Diamioglyoxime as Potential Burn Rate Modifiers in composite propellants
Authors: Stoner C. E. , Haggerty B. S. , Rheingold A. L. , Brill T. B. 
Published: May 2005

AbstractMetal complexes having the potential to modify the burn rate of rocket propellants are described. These are the diaminoglyoxime (DAG) complexes: Co(DAG–H)2·DAG, Cu(DAG–H)2·DAG, Ni(DAG–H)2 and Pd(DAG–H)2. The thermal decomposition was characterized by DSC, TGA and IR spectroscopy at a heating rate of 5°C/min, and by fast thermolysis/FTIR spectroscopy at 100–250°C/s. The M(DAG–H)2 complexes are more thermally stable than M(DAG–H)2·DAG. However, all of the compounds produce highly thermally stable residues which would be expected to retard the heat and mass transfer at a burning surface. The residues most closely resemble coordination complexes of the metal and polymeric cyclic azine compounds. The crystal and molecular structure of the previously unreported complex Ni(DAG–H)2·HCL is described.
Molecular orbital studies of the thermal decomposition mechanism of dimethylnitramine
Authors: Ling Yue , Tang Ze‐Hua , Xiao He‐Ming 
Published: May 2005

AbstractThe electronic structures of dimethylnitramine (DMNA) were calculated using ab initio Gaussian 80 program at the Hartree‐Fock level with STO‐3G and STO‐4‐21G basis set, respectively. The Mulliken bond order of the NNO2 bond is the least one in comparision with those of the other bonds in the DMNA molecule. Two potential energy curves along the NN bond splitting pathway (RNN) were obtained using MINDO/3 and MNDO methods, respectively. These curves have the same trend and are qualitatively consistent with the results obtained from the thermolysis of nitromethane (CH3NO2). It was found that the frontier MO levels and the net charges of groups are changed with RNN distance. The products of thermal decomposition and the energy changes were calculated by MINDO/3 method and are discussed in this paper.
LOVA Gun Propellants with GAP Binder
Authors: Schedlbauer Fritz 
Published: May 2005

AbstractFirst results will be presented in the field of LOVA gun propellants with polyglycidylazide‐binder system. Theoretical calculations and experimental investigations were carried out to get informations about the ballistic behavior of this type of gun propellant. Chemical stability and mechanical properties were also determined. In addition, the bullet impact test was performed. All these dta were compared with those of nitramine‐gun propellants based on HTPB.
Aging Behavior of Propellants investigated by heat generation, stabilizer consumption, and molar mass degradation
Authors: Bohn Manfred A. , Volk Fred 
Published: May 2005

AbstractFour double‐base rocket propellants and a single‐base gun propellant were tested to find out stabilizer consumption molar mass degradation, and heat generation between 50 °C and 90 °C and between 40 °C and 110 °C, respectively. Stabilizer depletion was measured by high performance liquid chromatography (HPLC), molar mass degradation by gel permeation chromatography (GPC), and heat generation by microcalorimetry. The conditioning times at different temperatures were determined with one of the rocket propellants, and the influence of the long‐term storage on heat generation at 60 °C for 2191 dys was investigated. A correlated experiment between stabilizer consumption and heat generation showed that heat production does not increase substantially until the stabilizer has been consumed almost completely. The experimental data of molar mass degradation are described by a kinetic model based on statistical chain scission, and the stabilizer decrease by a first order reaction. For the gun propellant the Arrhenius plots of the reaction rate constants show two temperatures of teh stabilizer consumption, molar mass degradation and heat generation were determined.
The Flow Characteristics of High Explosives
Authors: Akhavan J. , Welsh L. J. 
Published: May 2005

AbstractA comparative study of flow properties of the explosive compound RDX is presented. The results were used to identify desirable free‐flowing characteristics in the powders. Various static and free‐flowing tests were conducted on the explosive powders. The results suggest that flow properties of the RDX powders tested were not influenced by particle size and surface roughness. However density, moisture content and cohesive strength between the particles had some effect on the flow properties. An increase in moisture content and cohesive strength of the particles reduced the flow rate. Whereas an increase in bluk density of the powders increased the flow rate.
Urethane Reaction Mechanism on the Amorphous Boron Surface in GAP propellants
Authors: Oyumi Yoshio , Nakashita Goro 
Published: May 2005

AbstractThermal analysis and FT‐IR spectrometry were used to characterize the urethane reaction mechanism of polyglycidyl azide (GAP) propellants with powdered amorphous boron. The amorphous boron added GAP propellant with trimethylol propane (TMP) vigorously gassed of during the cure process and did not complete its urethane reaction. Although it was curable by excess amount of isocyanates, voids or bubbles were trapped inside the propellant grain. Since the powdered amorphous boron was relatively hygroscopic compared to other crystalline metal powders, it might contain boron surface impurities, namely, water, boric acid, and/or boron oxide which disturbed the urethane reaction. TMP was also relatively hygroscopic and played an interesting role on the propellant processing, which was used for cross‐link and surface treatment agent of powdered amorphous boron.
An Improved Simple Method of Deducing JWL Parameters from cylinder expansion test
Authors: Lan I‐Feng , Hung Sheng‐Chih , Chen Chun‐Yu , Niu Yih‐Ming , Shiuan Jonq‐Hwa 
Published: May 2005

AbstractA simple method which is much simpler than, while retaining the same degree of accuracy, as that of a large computer hydrocode has been developed for deducing the JWL equation of state (EOS) of high explosive detonation products from the cylinder expansion test.The radial expansion history of metal tube, which is recorded by the streak camera, is expressed as an appropriate fitting function with the aid of a nonlinear curve fitting procedure. The measured data with respect to Eulerian coordinate are transformed to that in Lagrangian coordinate so that the p‐V relation of detonation products may be obtained from the differentiation of fitting function and equations of conservation law. Metal strength is also taken into consideration to reduce the deviation at the lower pressure region. JWL parameters are acquired through the p‐V relations by another nonlinear curve fitting procedure.The computed results for Comp‐B, TNT, HMX, PBX‐9404 and nitromethane, which are in good agreement with Lawrence Livermore National Laboratory (LLNL) data, are listed for comparison with other procedures in literature which have been in use so far.
Quantitative Measurement of Propellant Stabilizers with tlc and liquid‐crystalline method of visualization
Authors: Miszczak Maciej , Bladek Jan 
Published: May 2005

AbstractBasic compounds of propellants, nitrate esters decompose forming nitrogen oxides as the catalytic products. To inhibit further decomposition, stabilizer reacts with nitrogen oxides, and finally non‐catalytic products are formed, so autocatalytic decomposition is minimized. In this way, chemical stability of propellant increases, but the content of stabilizer decreases.In this paper, the possibility of quantitative analysis of the weight loss of propellant stabilizer using the TLC method and the liquid crystal method of visualization is presented. The advantages of solid phase extraction (SPE) application in such analysis are also shown.
An Extension to the Critical Energy Criterion used to predict shock initiation thresholds
Authors: James H. R. 
Published: May 2005

AbstractIt has long been appreciated that the critical energy (Ec) criterion, developed by Walker and Wasley(1), has been limited in both the pressure range over which it applies(2), and in the number of explosive formulations which appear to obey it(3). The addition of a specific energy “cut‐off” to the criterion enables it to be applied to explosives previously considered to lie outside the original criterion, and to extend the range of impacts covered by the criterion in explosives which obey Ec within certain pressure limits. The new criterion appears particularly applicable to cast PBX formulations and insensitive high explosives such as TATB.
PBX 9502 Products Equation of State
Authors: Tang P. K. 
Published: May 2005

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 standard EOS.
Phase Transitions and Lattice Dynamics of Ammonium Nitrate
Authors: Herrmann Michael J. , Engel Walter 
Published: May 2005

AbstractAdvanced evaluation techniques as Rietveld refinement applied to series of temperature resolved X‐ray diffraction measurements, provide an improved insight into the lattice dynamics. The transition paths of ammonium nitrate are clearly defined and coexisting phases are quantitatively determined. The curves for the elementary cell parameters of the different phases as a function of temperature exhibit hitherto unknown details and elucidate expansion and transition mechanisms. They are used for the calculation of the volume changes during the transitions and the volumetric and linear expansion coefficients.
Disposal of Energetic Materials by Alkaline Pressure Hydrolysis and combined techniques
Authors: Bunte Gudrun , Krause Horst H. , Hirth Thomas 
Published: May 2005

AbstractDue to the reduction of armament and especially due to the German reunification we are met by the objective of the disposal of energetic materials. Environmentally friendly disposal methods available for the different propellants, explosives and pyrotechnics are urgently needed. The main component of gun and rocket propellants is the energetic polymer nitrocellulose. One method to dispose nitrocellulose containing propellants is the combination of rapid chemical destruction by pressure hydrolysis and the biological degradation of the reaction mixture. The study describes the results of pressure hydrolysis of different gun and rocket propellants. Under alkaline conditions (propellant to NaOH ratio 2.3:1; reaction temperature 150 °C; pressure below 30 bar) biological degradable reaction products were formed. The main products in the liquid phase were simple mono‐ and dicarboxylic acids. Dependent on the reaction conditions 30–50 % of the nitrogen content of the propellants was transformed to nitrite and nitrate. The gaseous nitrogen containing products were N2 (16–46 %), N2O (2–23 %), NOx (0–5 %). Overall 40%–60% of the propellant nitrogen was transformed to gaseous products. In the solid residues a nitrogen content between 2 % and 9 % was found. The residues were mostly due to additives used in propellant manufacturing. In the case of nitrocellulose pressure hydrolysis below 30 bar and reaction temperature about 150 °C are sufficient.
Formation of Particles of Explosives with Supercritical Fluids
Authors: Teipel Ulrich , Förter‐Barth Ulrich , Gerber Peter , Krause Horst H. 
Published: May 2005

AbstractThe particle properties of components of explosives and propellants, i.e. the particle size, the particle size distribution and the particle shape, are very important. Especially with regard to insensitive explosives, the formation of crystals without spots, i.e. free of solvent inclusions, is aspired. New processes, taking advantage of the special characteristics of high‐compressed respectively supercritical fluids, offer many possibilities to influence the properties of solid particles. For the RESS process (Rapid Expansion of Supercritical Solutions), the formation of particles results from the rapid expansion of a loaded supercritical fluid. The GAS process (Gas Anti‐Solvent) uses a high‐compressed fluid as anti‐solvent to lower the solvent power of a common solvent and thus to recrystallize the solid. In this report, the different processes to form particles of explosives and propellants with supercritical fluids are explained, and the first results are presented.
Combustion and Sensitivity Characteristics of Mg/TF Pyrolants
Authors: Kuwahara T. , Matsuo S. , Shinozaki N. 
Published: May 2005

AbstractBurning rate characteristics and sensitivity characteristics of energetic mixtures composed of metal particles and oxidizers, the so called ‘pyrolants’, were studied experimentally. The pyrolants tested were made of various particle sizes of magnesium (Mg) and polytetrafluoroethylene (TF). Mg/TF pyrolant produces high combustion flame temperature, so it is used as heat sources and igniter pyrolants. The maximum flame temperature (Tf) is 3271 K at 0.1 MPa, and 3483 K at 1 MPa. These values are obtained when Mg concentration is 30%. When the Mg concentrations are less than 50% the pyrolants are not able to burn stably at one atmosphere. The burning rate increases with increasing the concentration of Mg and decreases with increasing the mean diameter of Mg particles at constant pressure. Explosive energy evaluated with drop hammer test decreased with increasing burning rate, so there is strong relationship between burning rate and explosive energy.
The Electrothermal Enhancement of Propellant Burning by Plasma Injection
Authors: Proud W. G. , Bourne N. K. 
Published: May 2005

AbstractA series of experimental demonstrations of plasma injection into a burning propellant interface is presented. The propellant is a nitro‐guanidine based material in the form of a right cylinder with a bore along its central axis. It is ignited by a hot‐wire system and, when a pre‐set pressure is achieved, a second wire is exploded using a high‐voltage capacitor discharge circuit. The second wire forms a plasma, precisely at, or well away from the burning interface. Comparing the pressure histories from these different geometries allows the effect of increased burning rate to be separated from Joule heating of the product gases. Analysis of these histories shows a pressure increase over that caused by Joule heating of the products.