Showing papers on "Ammonium perchlorate published in 1971"
124 citations
01 Jan 1971
TL;DR: In this article, a model describing the combustion of composite propellants has been applied to three different types of composite powders, and to two oxidizers which burn as monopropellants.
Abstract: A model describing the combustion of composite propellants has been applied to three different types of composite propellants, and to two oxidizers which burn as monopropellants. The oxidizers studied are AP, HMX, and KP (ammonium perchlorate, cyclotetramethylenetetranitramine, and potassium perchlorate), each of which has unique combustion characteristics. The monopropellant combustion of AP and HMX has been considered in detail, particularly that of AP. Calculations have been compared with experimental data for the burning rate, the sensitivity of the burning rate to both pressure and initial temperature, and the surface temperature. The agreement between the calculations and experimental data is very adequate. The results indicate that AP and HMX apparently burn with a considerable exothermic reaction at the burning surface as well as in the gas phase above the surface. Both reactions must be accounted for to give consistent results. The combustion of the three oxidizers burning with a fuel in composite propellants has also been simulated. Experimental data are presented for propellants in which the oxidizer has been systematically varied. A direct comparison has been made between the data and the calculations of the model. The calculations agree quite well with the combustion characteristics of the three different types of composite propellants.
81 citations
TL;DR: In this paper, the authors investigated the dependence of the burning rate of ammonium perchlorate on pressure, namely, the initial growth of burning rate with pressure, the plateau or the rate drop, and the subsequent growth at high pressures.
49 citations
42 citations
01 Jan 1971
TL;DR: In this paper, the deflagration behavior of pure and doped ammonium perchlorate (AP) was studied over the pressure range 300-6000 psia, using cinephotomicrography of burning samples and scanning electron microscopy of quenched samples.
Abstract: The deflagration behavior of pure and doped ammonium perchlorate (AP) was studied over the pressure range 300–6000 psia, using cinephotomicrography of burning samples and scanning electron microscopy of quenched samples. Materials studied were pure AP in single-crystal and pressed-pellet forms, and single crystals with controlled isomorphous substitution of K + , MnO 4 − , and Cr 2 O 7 2− ions. This study shows that previous speculations regarding the combustion of AP are based on erroneous assumptions, and more realistic views, based on the observations, are proposed. In addition, some serious questions regarding the relevance of low-temperature, low heating rate, and low-pressure decomposition data to actual combustion are posed.
38 citations
36 citations
TL;DR: In this article, the quench combustion of two-dimensional propellant sandwiches prepared with AP oxidizer and four conventional propellant binders (polysulfide (PS), polyurethane (PU), polybutadiene acrylic acid (PBAA), and carboxy terminated polybutadene (CTPB) was investigated.
Abstract: In order to obtain information essential to the future success of analytical modeling of solid propellant combustion, an experimental investigation was conducted using the quench combustion of two-dimensional propellant sandwiches prepared with AP oxidizer and four conventional propellant binders—polysulfide (PS), polyurethane (PU), polybutadiene acrylic acid (PBAA), and carboxy terminated polybutadiene (CTPB). Propellant sandwiches, prepared with both single crystal sheets and compacted polycrystalline sheets, were burned and quenched at combustion pressure levels from 300 psig (20 kg/sq cm) to 2400 psig (163 kg/sq cm) for a range of binder lamination thicknesses varying between 25 and 200 microns. The features of the quenched sandwiches indicate that there is considerable interplay between the binder and oxidizer species on the oxidizer portion of the sandwich surface, primarily through the ability of the binder to form a flowable melt prior to gasification; sandwiches prepared with all four fu...
35 citations
TL;DR: In this paper, the decomposition and combustion of ammonium perchlorate are reviewed with particular emphasis on the chemistry of the process and on the role of catalysts, and the possible reaction mechanisms to attempt to select the specific areas requiring further investigation.
Abstract: Recent studies on the decomposition and combustion of ammonium perchlorate are reviewed with particular emphasis on the chemistry of the process and on the role of catalysts. This is used for a detailed discussion of the possible reaction mechanisms to attempt to select the specific areas requiring further investigation, both to extend the understanding of the combustion mechanism and to improve the basis of the theoretical models.
34 citations
Patent•
22 Feb 1971
TL;DR: In this paper, a solution of ammonium perchlorate in a volatile liquid with a second less volatile liquid which is miscible with the first liquid and is a non-solvent, is used to limit particle growth.
Abstract: Sub-micron particle size ammonium perchlorate particles are made by mixing a solution of ammonium perchlorate in a volatile liquid with a second less volatile liquid which is miscible with the first liquid and is a non-solvent for ammonium perchlorate. The resulting mixture is heated to vaporize the volatile liquid and form a suspension of fine ammonium perchlorate particles in the second liquid. A particle coating agent soluble in the second liquid is used to limit particle growth. The particles are coated with the coating agent and may be recovered from the suspension by vaporization of the second liquid to form a powder, or by partial evaporization of the second liquid to form a concentrated slurry or paste in which the ammonium perchlorate is the disperse phase. The ultra-fine particles formed are suitable for use in propellant formulations.
33 citations
28 citations
TL;DR: In this article, the authors studied the kinetics of reaction at the interface of gaseous fuel and catalyst-containing ammonium perchlorate (AP) and showed that surface-catalyzed reactions at the surface of the solid AP-CC yield a net exothermic heat release whose magnitude is a function of the partial pressure of the fuel and the concentration of CC catalyst.
Patent•
16 Mar 1971TL;DR: In this article, a process for preparing ultra-fine ammonium perchlorate particles is described, in which an aqueous solution of ammonium permchlorate is dispersed in an organic liquid to form a water-in-oil emulsion.
Abstract: A process for preparing ultra-fine ammonium perchlorate particles is provided. In this process an aqueous solution of ammonium perchlorate is dispersed in an organic liquid to form a water-in-oil emulsion. The emulsion is frozen and freeze dried to produce the ultra-fine particles.
TL;DR: In this article, high power interference contrast microscopy was used to examine the growth faces of ammonium perchlorate and found that the Burgers vector was known for all but one of the active slip planes.
Abstract: Cleavage and growth faces of ammonium perchlorate have been examined by high-power interference–contrast microscopy. From the observed directions of etch-pit arrays on three crystallographically distinct faces of the orthorhombic form of ammonium perchlorate, and also from the nature of the slip bands on deliberately deformed crystals, the nature of the dislocations present has been clarified. All the observed alignments and bands on the various faces may be accounted for in terms of dislocation movement on (20), (201), (401), (40), (110), (10), (010), and (001) planes, the direction of the Burgers vector being known for all but one of the active slip planes. Preferential evaporation occurs from dislocation cores emergent at (001) faces.
25 Jan 1971
TL;DR: In this paper, the authors investigated the sublimation of ammonium perchlorate using simultaneous differential thermal analysis and thermogravimetric analysis and found that the activation energy was in good agreement with that derived from the Schultz-Dekker theory (18±2kcal·mole−1).
TL;DR: In this article, current stability criteria for longitudinal combustion instability were tested for generality using data from 54 different propellants including polyurethane and carboxyl-terminated polybutadiene binders, ammonium perchlorate, aluminum, and rate modifiers.
Abstract: : Current stability criteria for longitudinal combustion instability were tested for generality using data from 54 different propellants. These included formulations containing polyurethane and carboxyl-terminated polybutadiene binders, ammonium perchlorate, aluminum, and rate modifiers. The propellants were tested at 70F in 4- and 8-in. diam, tubularly-perforated motors which were pulsed to initiate the instability. It was found that for a particular propellant system, well-defined behavioral trends could be established as the formulation was varied. A considerable variability in such trends was observed, however, for grossly different propellant systems. Consequently, a generalized correlation of motor behavior with the details of propellant formulation was not achieved. Similarly, the stability criterion proposed by Capener, Dickinson, and Kier, which features a power law relation between a 'threshold' burning rate and the corresponding chamber pressure, was found to be invalid in the general case. (Author)
TL;DR: In this paper, the effect of aluminum content and aluminum particle size on the burning of a stoichiometric mixture of ammonium perchlorate and polyformaldehyde was investigated, and it was established that:
Abstract: We have investigated the effect of aluminum content and aluminum particle size on the burning of a stoichiometric mixture of ammonium perchlorate and polyformaldehyde. It has been established that:
TL;DR: In this paper, the surface area of very fine ammonium perchlorate and solid burning rate catalysts was determined using the continuous flow gas adsorption (CGFG) method.
Abstract: : The determination of the surface areas of powders is of considerable importance for the quality control of composite propellants. For many years satisfactory control has been achieved by the use of an air permeability method but this was found unsuitable for very fine ammonium perchlorate and solid burning rate catalysts which are being used to an increasing extent in fast-burning compositions. Of the various methods considered for measuring the surface areas of these very fine powders, the continuous flow gas adsorption method appeared promising but had several disadvantages in operation. The report describes modification to the method which have removed the disadvantages. (Author)
TL;DR: In this paper, the ESR spectra of 14NH3+ radicals in γ-irradiated crystals of ammonium perchlorate were observed in the temperature range 77-300°K.
TL;DR: The thermal decomposition of perchloric acid has been investigated on five Harshaw catalysts: copper chromite, alumina, iron(III) oxide, copper(II) oxide and manganese(IV) oxide as discussed by the authors.
Abstract: The thermal decomposition of perchloric acid has been investigated on five Harshaw catalysts: copper chromite, alumina, iron(III) oxide, copper(II) oxide, and manganese(IV) oxide (the last three being supported on alumina). Manganese(IV) oxide gave complex kinetics which were not fully analyzed but on the other four catalysts the reaction was.first order. Activation energies were: copper chromite, 54 kcal/mol; alumina, 28.8 kcal/mol; iron(III) oxide, 28.6 kcal/mol; copper(II) oxide, 39.0 kcal/mol. A mechanism is proposed for the decomposition which involves proton transfer to an accepter (typically an O2− ion) in the catalyst surface followed by decomposition of the ClO4− anion formed in this process. Some observations on the catalyzed thermal decomposition of ammonium perchlorate are presented.
Patent•
15 Sep 1971TL;DR: In this article, a method of making finely particulate ammonium perchlorate which comprises establishing a two-phase liquid system in which the upper phase is a concentrated solution of ammoniumperchlorate and the lower phase is immiscible with the upper-phase solvent and a non-solvent for ammonium permacaulate.
Abstract: A method of making finely particulate ammonium perchlorate which comprises establishing a two-phase liquid system in which the upper phase is a concentrated solution of ammonium perchlorate and the lower phase is a liquid which is immiscible with the upper phase solvent and a non-solvent for ammonium perchlorate. Precipitation of ammonium perchlorate from the solution into the non-solvent is effected by either cooling the solution or evaporating the solvent thereof while subjecting the system to ultra-sonic vibrations. Fine ammonium perchlorate particles collect in the non-solvent phase and are recovered therefrom.
TL;DR: In this article, the authors considered possible mechanisms of retardation of the chemical reactions when ammonium nitrate and perchlorate burn and showed that one such mechanism is retardation by the water formed during combustion.
Abstract: We have considered possible mechanisms of retardation of the chemical reactions when ammonium nitrate and perchlorate burn and have shown that one such mechanism is retardation by the water formed during combustion.
TL;DR: Ammonium perchlorate (AP)/wax mixtures were used to model a simple composite propellant as discussed by the authors, which increased its infinite-diameter detonation velocity and its shock sensitivity, and decreased its critical diameter and its detonation reaction time.
TL;DR: In this article, it was shown that the radiation-induced effects can be attributed to dislocations which are generated during irradiation, which can be used to explain the dislocation in ammonium perchlorate.
Abstract: THE exposure of ammonium Perchlorate crystals to radiation before heating accelerates the decomposition rate and shortens the induction period1–4. Furthermore, the thermal, chemical and radiolytic decomposition of ammonium Perchlorate5–7 and the radiation-induced etching of NaN3 and KN3 (ref. 8), have been shown to be intimately related to dislocations. We wish to describe measurements indicating that the radiation-induced effects can be attributed to dislocations which are generated during irradiation.
Patent•
14 Oct 1971
TL;DR: An explosive adapted for field mix and comprising about ten parts by weight of a first ingredient in solid form which in ammonium nitrate or mixtures of ammonium ionate with a minor or equal amount of other oxidizer salt such as ammonium perchlorate or the like is described in this article.
Abstract: An explosive adapted for field mix and comprising about ten parts by weight of a first ingredient in solid form which in ammonium nitrate or mixtures of ammonium nitrate with a minor or equal amount of other oxidizer salt such as ammonium perchlorate or the like and about 1 part by weight of a second ingredient in liquid form which comprises about equal parts of hydrazine and water by weight.
Patent•
21 Apr 1971
TL;DR: In this article, solid solutions of the oxidizer with at least one other compound are provided which have improved thermal stability and which are particularly useful in explosive and propellant compositions, such as ammonium perchlorate and ammonium nitrate.
Abstract: Oxidizing compounds are provided which have improved thermal stability and which are particularly useful in explosive and propellant compositions. Such oxidizers are produced by making solid solutions of the oxidizer with at least one other compound. The solid solutions of particular interest for the purpose of this invention are ammonium perchlorate (NH4CIO4) and potassium perchlorate (KClO4), or ammonium perchlorate and ammonium nitrate (NH4NO3).
Patent•
06 Jul 1971TL;DR: A solid rocket propellant comprising ammonium perchlorate, alumin, poly(1,2-butylene) glycol, the reaction product of propylene oxide and either trimethylolpropane, hexanetriol or mixtures thereof, 2,3-dihydroxypropyl bis(2-cyanoethyl) amine, hexamethylene diisocyanate, copper chromite, and optionally containing (10) a metal acetylacetonate, (11) 2,4-pentanedione and (12) liquid silicon
Abstract: A solid rocket propellant comprising (1) ammonium perchlorate, (2) alumin (3) poly(1,2-butylene) glycol, (4) the reaction product of propylene oxide and either trimethylolpropane, hexanetriol or mixtures thereof, (5) 2,3-dihydroxypropyl bis(2-cyanoethyl) amine, (6) hexamethylene diisocyanate, (7) copper chromite, (8) a carboxylic acid ester of either a diol and a monocarboxylic acid or a dicarboxylic acid and a monofunctional alcohol, and (9) sulfur and optionally containing (10) a metal acetylacetonate, (11) 2,4-pentanedione and (12) liquid silicon oil.
TL;DR: In this article, the DTA thermograms show one endotherm corresponding to the structure transition at 240°C, and two exotherms at 320°C and 60°C.
Abstract: While 4 distinct endothermal processes are known to accompany the thermal decomposition of Ammonium Perchlorate (AP), the DTA thermograms show one endotherm corresponding to the structure transition at 240°C, and two exotherms. The different characteristic points of the DTA thermograms change with the thermal history of the sample and even with aging at ambient temperature. Periods of preheating at 150° lower the initial temperature of self-heating at a later heating from about 300° for freshly recrystallised AP to about 210° after preheating for 4 days at 150°C. Heating-cooling cycles above 200° (lower limit) up to 320° (upper limit) show for the first 2-3 cycles the influence of the known “limited decomposition” of AP. On cooling there is a temperature delay in the structure transition cubic orthorhombic, up to a constant limit of about 15°, and an apparent comminution of grains.
01 Jan 1971
TL;DR: In this article, an attempt was made to compare the catalytic effect of the oxides on the decomposition of perchloric acid and on that of ammonium perchlorate.
Abstract: The vapor-phase decomposition of perchloric, acid has been investigated for all the oxides previously studied in connection with the decomposition and combustion of ammonium perchlorate (AP). The experiments were carried out in a flow system, using N 2 as carrier gas. The interaction between the catalysts and the substratum was studied by electric-conductivity measurements, infrared spectroscopy, chemical and thermal analysis. The oxides catalyze the composition of perchloric acid in the temperature range between 130°–400°C, depending on the metal ion. For 0.5% to 8% conversion per minute, the catalytic decomposition followed first-order kinetics. An exception was chromium oxide, for which the reaction was found to be of zero order. The activation energies determined for the different catalysts ranged from 20 to 45 kcal/mode. A close relation had been observed between the catalytic effect of the metal oxides on the decomposition of HClO 4 and the thermal stabilities of the corresponding perchlorates, namely, that the most active oxides gave the most unstable perchlorates. An attempt was made to compare the catalytic effect of the oxides on the decomposition of perchloric acid and on that of ammonium perchlorate. Using the same catalyst in both cases, it was concluded that there is no direct correlation between the relative activity of the oxides in the two reactions.