Showing papers on "Ammonium perchlorate published in 2003"

Enhanced Propellant Combustion with Nanoparticles

Abstract: Enhanced burn rate results are presented for ammonium perchlorate/Al nanoparticle strand burners at atmospheric (and higher) pressure and for the comparative combustion in a high pressure closed vessel of a solid propellant containing 15% of either conventional micrometer-scale Al or nanometric Al The burn rate at the smallest nanometric Al particle size appears to be asymptotically approaching an inverse particle-diameter-squared dependence

Thermal Decomposition and Combustion of Explosives and Propellants

Abstract: INTRODUCTION KINETIC PROBLEMS OF DECOMPOSITION OF EXPLOSIVES AND PROPELLANTS References GENERAL REGULARITIES OF THERMAL DECOMPOSITION OF HIGH-ENERGY COMPOUNDS Gas Phase Reactions Liquid Phase Reactions Decomposition In The Solid State References ALIPHATIC NITROCOMPOUNDS Gas Phase Decomposition By The Molecular Mechanism Gas Phase Decomposition By The Radical Mechanism Competition Of The Radical And Molecular Mechanisms Reactions In The Condensed State References AROMATIC NITROCOMPOUNDS Gas Phase Decomposition By The Radical Mechanism Molecular Mechanism Of Decomposition Decomposition In The Liquid State Decomposition In The Solid State References SECONDARY NITROAMINES First Stage Of Decomposition Secondary Reactions Kinetic Data References ORGANIC AZIDES Aliphatic Azides Aromatic And Heterocyclic Azides References ORGANIC DIFLUOROAMINO COMPOUNDS References HETEROCYCLIC COMPOUNDS Thermal Decomposition Of Furazanes And Furoxanes Stability Of Tetrazoles References NITROESTERS References COMPOUNDS WITH MIXED FUNCTIONS References GENERAL REGULARITIES OF THERMAL DECOMPOSITION OF ONIUM SALTS, NITRIC AND PERCHLORIC ACIDS, DINITRAMIDE General Regularities Nitric Acid Perchloric Acid Ninitramide References AMMONIUM NITRATE General Regularities Influence Of Water, Acid, And Ammonia On The Decomposition Rate The Heat And Macrokinetic Regularities Of Decomposition Thermal Decomposition Below The Melting Temperature Influence Of Additives On The Rate Of Thermal Decomposition AMMONIUM PERCHLORATE Kinetics Of The Low-Temperature Decomposition Kinetics Of The High-Temperature Decomposition Influence Of Excessive Acids And Bases Topochemical Peculiarities Of Thermal Decomposition Influence Of The Preliminary Irradiation And Additives Thermal Decomposition Of Composite Ap-Based Systems References AMMONIUM DINTRAMIDE Decomposition In The Melt Decomposition In The Solid Phase References THE SALTS OF HYDRAZINIUM, HYDROXYLAMMONIUM, AND NITRONIUM Hydrazinium Nitrate And Chloride Hydrazine Iodide Hydrazinium Azide Hydrazinium Perchloriate And Diperchlorate Hydroxyl Mmonium Sulphate And Phosphate Hydroxylammonium Chloride Hydroxylammonium Perchlorate And Its Hydroxylamine Complex Hydroxylammonium Nitrate Nitronium Perchlorate References METAL PERCHLORATES AND NITRATES, METAL SALTS OF DINITRAMIDE Metal Perchlorates Metal Nitrates Metal Salts Of Ninitramide Decomposition Of Potassium Salt In The Liquid State Decomposition Of Potassium Salt In The Solid Phase Dinitramide Salts Of Other Metals References BASIC ASPECTS OF THE COMBUSTION MECHANISM COMBUSTION OF PURE SUBSTANCES: REACTIONS IN THE CONDENSED PHASE The Model With Dispersion Of The Solid Substance The Model With Foaming Of The Reacting Substance The Model With Evaporation Or Sublimation References COMBUSTION OF PURE SUBSTANCES: REACTIONS IN THE GAS PHASE References COMBUSTION OF PURE SUBSTANCES: REACTIONS IN THE CONDENSED AND GAS PHASES References COMBUSTION OF CONDENSED COMPOSITE SYSTEMS Quasihomogenous Composites Layered Systems Composite Propellants References

Azido Polymers—Energetic Binders for Solid Rocket Propellants

Abstract: High-energy solid rocket propellants are composite materials having a binder [hydroxy terminated polybutadiene (HTPB)], high-energy additives [e.g., ammonium perchlorate (AP)], and pyrolants (metal...

Perchlorate retention and mobility in soils

Abstract: Adsorption and release of perchlorate in a variety of soils, minerals, and other media were studied when the solid media were exposed to low and high aqueous solutions of perchlorate salts. Low level ClO4− exposure was investigated by subjecting triplicate 5.0 g portions of a solid medium (38 different soils, minerals, or dusts) to 25 mL of an aqueous ammonium perchlorate (NH4ClO4) solution containing 670 ng mL−1 (6.8 µM) perchlorate. This corresponds to a perchlorate-to-soil ratio of 3.4 µg g−1 (34 nmol g−1). At this level of exposure, more than 90% of the perchlorate was recovered in the aqueous phase, as determined by ion chromatography. In some cases, more than 99% of the perchlorate remained in the aqueous phase. In some cases, the apparent loss of aqueous perchlorate was not clearly distinguishable from the variation due to experimental error. The forced perchlorate anion exchange capacities (PAECs) were studied by soaking triplicate 5.0 g portions of the solid media in 250 mL of 0.20 M sodium perchlorate (NaClO4) followed by repeated deionized water rinses (overnight soaks with mixing) until perchlorate concentrations fell below 20 ng mL−1 in the rinse solutions. The dried residua were leached with 15.0 mL of 0.10 M sodium hydroxide. The leachates were analyzed by ion chromatography and the perchlorate concentrations thus found were subsequently used to calculate the PAECs. The measurable PAECs of the insoluble and settleable residua ranged from 4 to 150 nmol g−1 (µmol kg−1), with most in the 20–50 nmol g−1 range. In some soils or minerals, no sorption was detectable. The mineral bentonite was problematic, however. Overall, the findings support the widely accepted idea that perchlorate does not appreciably sorb to soils and that its mobility and fate are largely influenced by hydrologic and biologic factors. They also generally support the idea that intrasoil perchlorate content is depositional rather than sorptive. On the other hand, sorption (anion replacement) of perchlorate appears to occur in some soils. Therefore, the measurement of perchlorate in soils requires accounting for ion exchange phenomena; leaching with water alone may give inaccurate results. If perchlorate anion exchange is confirmed to be negligible, then leaching procedures may be simplified accordingly.

Plateau Burning Behavior of Ammonium Perchlorate Sandwiches and Propellants at Elevated Pressures

Abstract: Further results on combustion of sandwiches made of alternating layers of ammonium perchlorate (AP) and a matrix of AP particles in polymeric binder in an expanded pressure range of 0.345-13.78 MPa (50-2000 psig), over a wide range of matrix lamina thicknesses, are reported. Inclusion of a nanoparticle-size burning rate catalyst in the matrix is also considered. The sandwich burning rates indicate plateaus over the 6.89-13.78 MPa (1000-2000 psig) pressure range for select ranges of matrix lamina thickness. These are correlated with similar plateau trends in the burning rates of composite propellant formulations with bimodal particle size distribution of the oxidizer and appropriate choice of coarse AP size, wherein the fine AP/binder matrices are of identical composition to those tested in the sandwiches. The dependence of the sandwich burning rates on the matrix lamina thickness and the quenched surface features are examined to explain the plateau burning rate trends. The results indicate that the two-dimensional coupling of heat feedback from the hot, near-surface parts of the oxidizer/fuel diffusion flamelets is diminished at elevated pressures due to their greater proximity to the burning surface and the corresponding shrinking of their lateral extent.

Electrochemical dechlorination of chlorinated hydrocarbons: Electrochemical reduction of chloroform in acetonitrile/water mixtures at high current density

Abstract: Electrochemical reduction of chloroform was studied in 0.1 M (1 M = 1 mol dm−3) tetraethyl ammonium perchlorate solutions of acetonitrile–water mixture using various metal electrodes. High water concentration (1 M) promoted the electrolysis with the products mainly CH4 and CH2Cl2. The partial current density of CH4 formation amounted to 0.3 A cm−2 at an Ag electrode.

Explosive composition and its use

Abstract: An explosive composition comprises a porous fuel and an oxidizer. The porous fuel is a solid with a structure size measuring between about 2 nm and 1000 nm and has a porosity that lies between 10% and 98%. The oxidizer is solid or liquid at room temperature and is incorporated into the pores of the porous fuel. The oxidizer is selected, in an amount of at least 50% by weight relative to a total quantity of the oxidizer, from the group consisting of hydrogen peroxide, hydroxyl ammonium nitrate, organic nitro compounds or nitrates, alkali metal nitrates or earth alkali metal nitrates as well as metal nitrites, metal chlorates, metal perchlorates, metal bromates, metal iodates, metal oxides, metal peroxides, ammonium perchlorate, ammonium nitrate and mixtures thereof.

The ignition of ultra-fine aluminum in ammonium perchlorate solid propellant flames

Abstract: A preliminary experimental investigation was carried out to investigate the ignition of ultrafine aluminum (UFAl) compared to conventional sized aluminum (CSAl) particles in ammonium perchlorate (AP)-polybutadiene acrylonitrile acrylic acid (PBAN) solid propellants. To evaluate the temperature criteria for igniting UFAl, matrix samples (binder, fine AP and Al only) were prepared with various loadings of 10μm fine AP (fAP) as a means of varying the AP-binder flame temperature, and with Al coarse-to-fine ratio of 0(30μm)/20(UFAl) and 80(30μm)/20(UFAl). Preliminary results showed that UFAl sized particles ignite at lower gasphase flame temperatures than CSAl particles and that the UFAl particles tend to affect the combustion processes close to the propellant surface depending upon the availability of oxidizer. * Senior Combustion/Propulsion Engineer. AIAA Member. E mail: allandokhan@hotmail.com † ‡ Regent Professor Emeritus. Fellow Member. Associate Professor. Senior Member. E mail: jerry.seitzman@ae.gatech.edu Senior Research Engineer. INTRODUCTION In recent studies of ultra-fine aluminum (UFAl~0.1μm) in ammonium perchlorate (AP) solid propellants with bimodal AP (10μm:400μm and 82.5μm:400μm) and bimodal aluminum (Al) distribution (30μm:UFAl), the burning of UFAl was found to create a very dense aluminum burning region (ABR) directly above and some distance beyond the propellant surface (~3000-4000μm) compared to the burning of conventional sized aluminum (CSAl~12-100μm). The density of the ABR was found to be the product of the number of burning Al particles/droplets/agglomerates leaving the propellant surface per unit area (one 30μm Al particle is the mass equivalent of 10 UFAl particles), which is very dependent upon the propellant microstructure (see later). The combustion of fine Al (~3μm) and UFAl particles occur much closer behind the AP-binder flame because of their near equilibrium state with the gas flow (temperature & velocity) compared to CSAl. As a result, they ignite quickly as they pass through the flame surface and burn close behind the convoluted flame canopy. This dense luminous bright ABR was found to be responsible for a significant amount of heat feedback to the propellant surface and to the AP-binder flame array in the form of either radiation and/or conduction, which resulted in high burning rate propellants. Copyright© 2003 A. Dokhan, E. W. Price, J. M. Seitzman and R. K. Sigman. Published by the American Institute of Aeronautics and Astronautics, Inc. with permission 1

Flash-ignitable energetic material

Abstract: Carbon nanotubes and activated carbon containing a metal such as palladium release a photoacoustic effect when subjected to a flash of light. A light ignitable, energetic composition is produced by mixing one of them with an energetic material such as carbon black powder or ammonium perchlorate.

Solid compositions which generate hydrogen by combustion, comprising an alkali metal borohydride or alkaline earth metal borohydride and an oxidizing salt based on ammonium perchlorate, alkali metal perchlorate or alkaline earth metal perchlorate

Abstract: The invention relates to a solid composition which can decompose with the generation of hydrogen according to a self-sustaining combustion reaction after initiation of this reaction by an appropriate heat source, this composition being characterized in that it comprises an alkali metal borohydride or alkaline earth metal borohydride and a perchlorate-based oxidizing salt corresponding to the general formula XClO4 in which X represents the NH4 group, an alkali metal or an alkaline earth metal.

A numerical study of periodic sandwich propellants with oxygenated binders

Abstract: We examine sandwich propellants constructed from sheets of pure ammonium perchlorate (AP) interleaved with an AP/binder blend, and construct solutions numerically using a code that fully couples gas-phase and solid-phase processes via an unsteady moving interface. This code has been used elsewhere to simulate the burning of random packs of spherical AP particles embedded in binder. We show that for a stoichiometric configuration, variations of the burning rate with α (a measure of the oxygenation of the AP/binder blend) are not monotonic, but display a weak maximum; and variations of the burning rate with sandwich thickness are monotonic for small α, but display a minimum for large α (e.g. α = 0.5). When the equivalence ratio is varied, the burning rate displays a maximum on the fuel-lean side when α is small, on the fuel-rich side when α is large. These results, and the manner in which the sandwich topography varies with the different parameters, suggest that the configuration could be invaluable for val...

Erosive Burning of Ammonium Perchlorate/Hydroxyl-Terminated-Polybutadiene Propellants Under Supersonic Crossflows

Abstract: An experimental procedure adopted for measuring the erosive burning in solid propellants under transonic and supersonic crossflow Mach numbers is explained. Three formulations of ammonium perchlorate/hydroxyl-terminated-polybutadiene propellants of different burning rates (6, 9, and 16 mm/s at 5 MPa) were used for the study. The study presents the erosive burning results for a range of crossflow Mach numbers from 0.8 to 1.7. Additionally, the adopted experimental procedure clearly demonstrates the choking station movement in grain ports of nozzleless motors. As observed under subsonic crossflow conditions, in supersonic conditions the following conditions hold: 1) The erosive burning effect increases with the increase in both pressure and free stream velocity of crossflow. 2) The propellants with lower normal-burning rates experience greater erosive burning than those with higher normal-burning rates. Negative erosive burning under supersonic crossflow velocities is identified at low pressures.

Computational models of combustion of nonmetallized heterogeneous propellant

Abstract: Physical and chemical models are treated which are employed for numerical analysis of the processes of combustion of nonmetallized sandwich heterogeneous propellants on the basis of ammonium perchlorate and hydroxyl-terminated polybutadiene.

Computational models of combustion of nonmetallized heterogeneous propellant

Abstract: Physical and chemical models are treated which are employed for numerical analysis of the processes of combustion of nonmetallized sandwich heterogeneous propellants on the basis of ammonium perchlorate and hydroxyl-terminated polybutadiene.

Nano/HEDM Technology: Late Stage Exploratory Effort

Abstract: : This work is focused on a continued, escalating effort to develop new energetic functional groups which offer enhanced energy, oxygen balance, and density in that order of priority. A continuation of the study of addition of nitrene precursors to N,N-dialkyl nitrosamines is described; the nitrene derived from 1-amino-3,5-dinitro-1 ,2,4-triazole has been approached by oxidation of the parent amine. Initial results were not successful; aminodinitrotriazole in the presence of lead tetra-acetate does not produce detectable yields of dinitrotriazolyl azoxy dimethyl amine when aminodinitrotriazole and lead tetra-acetate are reacted in the presence of N,N-dimethylnitrosamine. The synthesis of the 5-nitrotetrazole-2-N-oxide anion has been realized and optimized; it is carried out in water/potassium acetate buffer, and proceeds in 90% yield; due to the small enthalpy of this oxidation, scale up and heat dissipation do not present a problem. The density of hydroxyl ammonium 5-nitrotetrazole-2-oxide is 1.82 g/cc; its enthalpy of formation is +40 kcal/mole. Finally, a practical pathway to 1-alkoxy-5-amino tetrazoles has been developed; it is hoped that this will enable the synthesis of 5-nitrotetrazole-1 ,3-bis-N-oxides, a family of unprecedented materials with excellent heats of formation and oxygen balance that rivals ammonium perchlorate and ammonium dinitramide.

Combustion and Thermal Studies on Al/Ti/Ni/Zr Composite Modified Double-Base Systems

Abstract: Slurry-cast metallized ammonium perchlorate (AP)-composite modified double-base (CMDB) propellants incorporating Ni, Ti, and Zr were studied. Aluminized formulations were investigated as reference. Selected ballistic modifiers, namely, copper chromite (Cu-chromite)/ferric oxide (Fe 2 O 3 )/ferric acetyl acetonate (FeAA)/basic lead salicylate (BLS)+Cu 2 O+carbon black (C-black) combinations were also evaluated for their effectiveness. An acoustic emission technique was applied to determine the burning rates in the pressure range of 1-10.8 MPa, and thermal data were generated by applying differential thermal analysis, thermogravimetry, and differential scanning calorimetry techniques. The control formulation based on 30% AP dispersed in a 70% double base matrix, gave stable combustion in the entire pressure range studied. Inclusion of metals (2.5-17.5% at the expense of AP) resulted in a decrease in the burning rates with the increase in metal content. Ni-based formulations exhibited burning rates superior to aluminized formulations particularly with high metal content. The overall best burning-rate results were obtained with Zr, followed by Ti. Among ballistic modifiers, Cu-chromite was found to be the most effective, followed by the BLS + Cu 2 O + C-black combination. An interesting composition with super-burning-rate characteristics (10-60 mm/s in the 1-10.8 MPa pressure range) emerged during the research. Thermal studies show the heat sink effect of metals. However, Ni, Ti, and Zr appear to produce compensating heat feedback to a greater extent than Al. Cu-chromite appears to be highly effective in facilitating both condensed- and gas-phase combustion reactions.

High energy solid propellant

Abstract: The present invention provides a high energy solid propellant containing an oxidizer, binder and fuel, wherein the fuel and/or the propellant as a whole is encapsulated or microencapsulated so as prevent premature reaction while still maintaining the energetic properties thereof. The oxidizer is preferably ammonium perchlorate, ammonium nitrate or ammonium dinitramide. The binder is preferably polymeric hydrocarbons or polymers. The fuel is preferably lithium hexahydridoborane or lithium hexahydridoalane.

Modeling of microscale solid propellant combustion

Abstract: The numerical procedure for the burning of Ammonium Perchlorate (AP) with a Fuel-Binder (Hydroxyl Terminated Polybutadience HTPB) heterogeneous propellant is presented. This model accounts for the one-step reaction mechanism for the primary diffusion flame between the decomposition products of the Binder (B) and the oxidizer AP and allowed for the complete coupling between the gas-phase physics, the condensed-phase physics, and the unsteady non-uniform regression of the propellant surface. The parameters used in this model are fitted to experimental data for the combustion of AP/Binder. The propagation of the unsteady non-planer regression surface is described, using the Essentially-Non-Oscillatory (ENO) scheme with the aid of the level set strategy. The Alternating-Direction-Implicit (ADI) solver is employed to solve the full Navier-Stokes equations in the gas phase. The results show the effect of various parameters on the surface propagation speed, flame structure, and the burning surface geometry. A comparison between the computational and experimental results is presented.

Solid propellant composition with low sensitivity to projectile impact

Abstract: PURPOSE: Provided is a solid propellant composition for a rocket propulsion system, which has low sensitivity to projectile impact and satisfies the requirement defined by the friability test among the UN Test Series 7. CONSTITUTION: The solid propellant composition comprises: 45-97.5% of at least one filler selected from the group consisting of ammonium nitrate, hexanitro hexaaza isowurtzitane, phase stabilized ammonium nitrate, ammonium dinitramide, cyclo trimethylene tetranitramine, cyclotrimethylene trinitramine and ammonium perchlorate; at most 20 wt% of at least one prepolymer selected from the group consisting of hydroxy terminated polyether and hydroxy terminated polybutadiene; 0.5-10% of butacene as a catalyst; and 2-15% of bismuth trioxide.

(m-Carboxy­phenyl)­ammonium perchlorate at 223 K

Abstract: The title compound, C7H8N+·ClO4−, is built up from (m-carboxy­phenyl)­ammonium cations and perchlorate anions. Crystal cohesion is ensured by strong cation–anion and cation–cation hydrogen bonds, between the carboxyl­ic acid groups of the organic cations and the O atoms of the anions, and also between amine groups and carboxyl­ic acid groups.

Connections to Chemical Reaction Types

Abstract: This chapter discusses several issues related to chemical reactions, such as oxidation–reduction (redox) reactions, precipitation and dissolution, thermal decomposition, and photodecomposition. These issues are provided with their chemical basics and chemical details. One of the issues is why there is abundant white smoke from the space shuttle booster rockets on their lift-off. The ignition provided by the reaction of the solid aluminum powder and ammonium perchlorate powder generates a finely divided white powder known as alumina, various gases, and an extensive amount of heat. The dispersal of the white powder in the gases streaming from the boosters creates the billowy white appearance. In the formation of alumina, three elements, namely, aluminum, nitrogen, and chlorine undergo changes in oxidation number and two of the oxidation–reduction reactions occur. In both reactions aluminum is oxidized from the zero oxidation state to the +3 oxidation state, and chlorine is reduced from the +7 to the –1 oxidation state.

Microcombustors Based on Controllable Solid Fuel Elements

Abstract: This paper focuses on the control of solid-fuel burn rate by controlling the solid-fuel chemistry or by controlling heat losses. Laser cutting and lamination have been used to fabricate milli-scale test structures to characterize burn rates of composite solid fuel. The base ingredients for the solid fuels tested were phase-stabilized ammonium nitrate (PSAN), ammonium perchlorate (AP), and sodium azide (SA). These base ingredients were tested alone or mixed with hydroxyl-terminated poly-butadiene (HTPB) plus various accelerants. Several experiments were performed to test the controllability of composite solid fuels. Burn-rate tests at atmospheric pressure consisted of 250 to 500 micron deep square combustion chambers packed with fuel and resistively heated on the top surface until combustion was achieved. Experiments were also performed to increase burn rate through chamber pressurization. Reaction times for a set amount of fuel were observed to increase exponentially as nozzle diameter was decreased. Finally, combustion chamber geometry was altered to control reaction propagation by increasing localized heat losses. A 500 micron thick triangular chamber was fabricated and ignited at the larger end, allowing the reaction to propagate toward the triangle tip. These results indicate that controllable actuation of solid propellants on the microscale for non-thrust, gas generation actuator applications is feasible.Copyright © 2003 by ASME

Process for the production of perchlorate and composition comprising the same

Abstract: Production of free-running perchlorate comprises (a) mixing particulate perchlorate (I) with particulate surface-active anticaking agent(s) (II), (b) transferring the mixture to an inert carrier gas (III) stream and (c) hammer milling the mixture in the (III) stream. Independent claims are also included for the following: (1) free-running composition of (I) with a particle size less than 10 microns and homogeneous distributed, finely particulate (II); (2) solid propellant containing ammonium perchlorate of different particle sizes less than 50 microns, with a predominant fraction of the specified composition, a polymeric binder and aluminum.