Showing papers on "Ammonium perchlorate published in 1973"

Pyrotechnic composition with combined binder-coolant

Abstract: This pyrotechnic composition is adapted, upon combustion, for generating a low-flame temperature, non-toxic gas for inflating a vehicle safety bag. The composition comprises: a fuel, such as a carbonaceous material, aluminum or magnesium; an inorganic oxidizer, such as a metal chlorate, a metal perchlorate, a metal nitrate, ammonium chlorate, ammonium perchlorate or ammonium nitrate; and a combined binder and coolant, such as magnesium hydroxide or a mixture of magnesium hydroxide and magnesium carbonate. A typical example of this composition comprises: carbon as the fuel; potassium chlorate as the oxidizer; and a mixture of magnesium hydroxide and magnesium carbonate as the binder-coolant. One may use as much of this binder-coolant as is necessary to obtain the desired binding properties in the composition, without raising the flame temperature of the gas to an unacceptable level.

Ammonium Perchlorate Combustion: Effects of Sample Preparation; Ingredient Type; and Pressure, Temperature and Acceleration Environments

Abstract: Differences in ammonium perchlorate (AP) combustion behavior as evidenced by the effects of pressure, sample temperature and acceleration environments on burning rate are shown for samples prepared in various manners. The sample preparation parameters investigated include pellet compaction time and pressure, the particle sizes of the AP powder from which samples were pressed, and the type of AP (ultra-pure, propellant grade, and propellant grade with conditioners) from which the pellets were made.

Freeze drying process of making ultra-fine ammonium perchlorate and product

Abstract: Manufacture of ultra-fine ammonium perchlorate for incorporation into propellants, including the steps of A. FORMING AN AQUEOUS SOLUTION OF AMMONIUM PERCHLORATE (AP), and admixing said solution with an organic liquid immiscible with water and substantially a nonsolvent for AP, b. incorporating into the resulting admixture a branched chain hydroxy terminated polybutadiene (HTPB) having a molecular weight not exceeding about 2500, and a defined diester, and agitating the resulting water, AP, diester, and HTPB to form an emulsion comprising said organic liquid as continuous phase and said aqueous ammonium perchlorate solution as dispersed phase, C. FREEZING THE EMULSION, D. SUBLIMING THE ORGANIC LIQUID AND ICE FROM THE FROZEN EMULSION, AND E. RECOVERING RESIDUAL ULTRA-FINE AMMONIUM PERCHLORATE PARTICLES AS PRODUCT OF THE PROCESS. A composite propellant containing, as a binder, a branched chain HTPB having a molecular weight not exceeding about 2500, a defined diester as a plasticizer, and finely ammonium perchlorate as an oxidizer produced in accordance with process above described. Ultra-fine ammonium perchlorate produced in accordance with process above described.

Pot life extension of isocyanate cured propellants by aziridine compounds

Abstract: The reaction products formed from tri-functional aziridinylphosphine oxidesr their derivatives reacted with monofunctional carboxylic acids, the tri-aziridinyl derivatives of triazine, the tri-aziridinyl derivatives of benzenetriacyl, the aziridine compound N-phenethylaziridine, and selected alkyl diaziridine compounds are representive of the aziridine compounds which are utilized in isocyanate curable composite propellant compositions to extend usable pot life required for mixing and processing of the specified compositions. The compositions are comprised of a binder of hydroxy terminated liquid polymer systems, (e.g. hydroxy terminated polybutadiene and the like) selected plasticizers, optional metal fuel, and the inorganic oxidizer, ammonium perchlorate, that is substantially of very fine particle size (less than 20 microns).

Solid propellants with stability enhanced additives of particulate refractory carbides or oxides

Abstract: Ammonium perchlorate propellants utilizing a polybutadiene binder provide a smokeless exhaust and burn stably in a motor at a burning rate above 0.40 in/sec at 1,000 psia with no combustion instability if they include 0.25-5% of refractory metal carbides or oxides and carbon in the form of hollow, broken or unbroken carbon spheres, carbon particles or carbon flakes.

Catalytic Effects in the Combustion of AP-HTPB Sandwiches to 3200 PSIA

Abstract: An experimental sandwich study was conducted using hydroxyl terminated polybutadiene (HTPB) binder, compacted polycrystalline ammonium perchlorate (AP) and the catalysts copper chromite (Harshaw Catalyst CuO202) and iron oxide (ferric oxide). Cinephotomacrography at a latent magnification of 2:1 was used, and the pressure range studied was 600 to 3200 psia. Catalysts were added in the binder, in the oxidizer, or at the binder-oxidizer interface. Several conclusions concerning the mechanism of catalytic activity and the behavior of composite propellants were deduced from a careful examination of the film and the associated sandwich burn rates. Comparisons were made between previous results, obtained with carboxyl terminated polybutadiene (CTPB) at 600 and 2000 psia, and the present study using HTPB.

Pyrotechnic formulation with free oxygen consumption

Abstract: This pyrotechnic composition is adapted, upon combustion, for generating a low-flame temperature, non-toxic gas to inflate a vehicle safety bag. The pyrotechnic composition comprises: a fuel, such as a carbonaceous material, aluminum or magnesium; a coolant, such as a metallic carbonate; and an inorganic oxidizer, such as a metal chlorate, a metal perchlorate, a metal nitrate, ammonium chlorate, ammonium perchlorate or ammonium nitrate. In some instances, a metallo-organic compound, such as nickel formate, may be used as the fuel in mixture with or in place of the carbonaceous material, or the aluminum or the magnesium.

Pyrolysis and oxidation of polymers at high heating rates

Abstract: A high-heating-rate, thermoanalytical technique was developed and applied in an investigationof the pyrolysis and oxidation of nine polymeric fuel binders typical of those used in composite propellants. The experimental method permitted detection and measurement of energy effects from reactions in samples heated nearly uniformly at rates from 50° to 300°K/sec. Tests were performed at pressures from 0.02 to 6.85 atm. The results of the high-heating-rate pyrolysis tests in a neutral atmosphere were different from those obtained by conventional laboratory techniques at low heating rates. Although in either case the energy effects were small compared to oxidation effects, a change in the pyrolysis mechanism with heating rate was apparent. Tests in which the polymers were oxidized either with gaseous oxygen or by the decomposition products of admixed ammonium perchlorate showed evidence of an exothermic reaction at a temperature 100° to 150°K below the sample ignition temperature. Although significant heating resulted from this reaction, it apparently became reactant limited and may be an essential precursor to the strongly exothermic runaway ignition reaction.

Preparing oxidizer coated metal fuel particles

Abstract: Solid propellant composition of improved efficiency including an oxidizer, particularly ammonium perchlorate, and a powdered metal fuel, preferably aluminum or beryllium, in the form of a composite, the powdered metal fuel being contained in the crystalline lattice framework of such oxidizer, and hence being occluded within the oxidizer particles, as well as being disposed in the interstices between the oxidizer particles of the composition, such propellant composition produced by a process comprising crystallizing ammonium perchlorate in water, in the presence of finely divided aluminum or beryllium. A suitable binder is incorporated in the propellant composition to bind the individual particles of metal and particles of oxidizer containing occluded metal, together.

Vacuum Sublimation of Ammonium Perchlorate.

Abstract: : Time-of-flight measurements have been made on the flux of molecules from the surface of ammonium salts vaporizing into vacuum. As expected with ammonium halides and ammonium bi-sulfate the TOF distributions correspond to equimolar fluxes of ammonia and the corresponding acid. In the case of ammonium perchlorate the vapor subliming from a single crystal comprised ammonia and perchloric acid. When the source was compressed powder, the vapor was a mixture of lower molecular weight species. This result seems best explained in terms of subsurface decomposition. (Author)

Composite modified double base propellant with metal oxide stabilizer

Abstract: Composite-modified double base propellants containing an oxide of a metal selected from the group consisting of cadmium, magnesium, aluminum, tin, lead, titanium, and zirconium. These metal oxides are compatible with ammonium perchlorate, act as a thermal stabilizer, and act as a gas inhibitor if a polyfunctional isocyanate is used as a cross linking agent.

Extinguishment of Composite Propellants at Low Pressures

Abstract: : Propellants containing ammonium perchlorate and several commonly used polymer fuels were extinguished at low pressures. The extinguishment pressures were found to be strongly affected by the thermal environment, being lower when external flux compensated for heat loss. With a fixed thermal environment and extinguishment during depressurization, it was found that at very low depressurization rates, the extinguishment pressure depends on the rate in a manner suggesting energy starvation at the zone of first reactions. At the very low pressures, extinguishment appears to be caused by an intrinsic combustion instability featuring out-of-phase oscillations in the gasification rates of oxidant and polymer.

Propellants and pyrotechnic compositions containing aluminum-coated ammonium perchlorate

Abstract: A method for improving the combustion efficiency, i.e. increasing the burning rate, of propellant, flare, and other pyrotechnic compositions is disclosed which comprises using at least some ammonium perchlorate oxidizer coated with aluminum metal in place of a mere mixture of aluminum and ammonium perchlorate. The resultant compositions have increased burning rate in comparison to mere mixtures of ammonium perchlorate and aluminum.

Siloxane-coated ammonium perchlorate and propellant compositions made therewith

Abstract: Ammonium perchlorate particles having strongly adherent wettable coatings are made by treating the particles with stong amines that displace ammonia to form amine perchlorates at the particle surfaces. Silanylamines are preferred since after amination of the perchlorate the silane groups can be hydrolyzed to siloxanes having good wettability by liquid polymeric propellant binders. The coated perchlorate can be used to produce solid propellants having improved mechanical properties and burning characteristics.

Effects of copper chromite and iron oxide catalystson AP/CTPB sandwiches

Abstract: Results are presented of an experimental motion-picture study designed to provide observations of catalyzed composite solid-propellant combustion. Various methods of catalyst addition were incorporated into two-dimensional sandwiches, composed of pressed ammonium perchlorate (AP) oxidizer sections laminated together with a thin layer of carboxy terminated polybutadiene (CTPB) binder. Catalysts investigated were harshaw Catalyst Cu 0202 (copper chromite—CC) and Fe 2 O 3 (iron II oxide—IO). The sandwiches were burned in a window bomb at pressures of 600 and 2000 psig. Cinephotomacrography, at a frame rate of 1600 pictures per second and magnification of 2:1, was used. Copper chromite was found to be a more effective catalyst than IO for AP/CTPB sandwich systems. Copper chromite appeared to: augment the AP-deflagration process; possibly catalyze gas-phase reactions; possibly promote gas-phase reactions in crevices between the solid fuel and solid AP (at the interface); not promote heterogeneous reactions of gases with the solid-fuel binder; not modify the pyrolysis mechanism of the solid-fuel binder. Iron oxide was found to have effects qualitatively similar to CC, with the exception that it inhibited the AP-deflagration process at 600 psig. With the exception of IO at low pressures (600 psig), the addition of CC and IO in the AP was found to be the most effective method of increasing sandwich burn rate; their addition at the AP/binder interface was less effective; and their addition in the binder did not appear to be very effective at all, at least in the sandwich configuration. These findings, concerning CC and IO catalysts, indicate that some of the theories concerning the catalytic mechanisms of CC and IO with AP/binder composite propellants are justified, whereas others are not.

Mechanisms of Combustion.

Abstract: : ITE PROPELLANTS, BINDERS, DEFLAGRATION, MATHEMATICAL MODELS, AMMONIUM PERCHLORATEPOLYBUTADIENEThe report summarizes studies of the combustion of ammonium perchlorate-polymeric binder-ammonium perchlorate sandwiches. The first section describes the combustion of sandwiches utilizing polyurethane, carboxyl-terminated polybutadiene, hyroxyl-terminated polybutadiene, or polybutadiene acrylic acid binders. The second section deals with the deflagration of sandwiches with Fe2O3 or Harshaw CuO2O2 catalysts incorporated in the ammonium perchlorate, the HTPB binder, or at the AP-HTPB interface. The third section is concerned with the combustion of sandwiches incorporating as-received or a special preoxidized aluminum within the HTPB binder. The final section is comprised of an analytical modeling of the sandwich combustion. (Author)

Stabilization of Cure Rates of Diisocyanates with Hydroxy-Terminated Polybutadiene Binders

Abstract: : The purpose of the study was to define the catalytic effect of various propellant ingredients or potential additives on the rate of reaction of a model alcohol-isocyanate reaction. The object was to define those species and factors which contribute to a short pot-life in hydroxy-terminated polybutadiene (HTPB) bound propellants and to test various means of sequestering these species or, alternatively, of removing them. Studies of the effects of various catalysts on the reaction between alkyl isocyanates and alcohols have been carried out. In general, substances soluble in the reactants are more effective catalysts with organoiron derivatives being the most effective of those studied. The reaction was found to be light-assisted and ferrocene was shown to be a catalyst both in the presence of and in the absence of light. Ferrocene and its derivatives are degraded by light in the presence of air and by ammonium perchlorate.

Method for preparing small particle size coated ammonium perchlorate

Abstract: A method for preparing aziridine coated ammonium perchlorate (AP) of weightedian diameters (WMD) ranging from about 0.25 to about 5.0 micrometers is disclosed. The method employs either an unlined stainless steel or a polyurethane lined vibro-energy grinding mill wherein a high purity aziridine compound is used as the grinding aid and the coating agent for the AP. The coated AP product extends the pot-life for hydroxyterminated polybutadiene (HTPB) propellant formulations.

Pyrotechnical mixtures - for intermittent emission of light

Abstract: The compsns. esp. suitable for flares and signals in sea or mountain rescue, in military operations, or fireworks, are made by mixing an oxidising agent, esp. the nitrate and/or perchlorate of an alkali(ne earth) metal, ammonium perchlorate, and a two-component metallic reducing agent. The latter is made esp. from Al-Mg. For coloured emission, the nitrate and/or perchlorate of Ba, Sr, Na, K are used. Moderating agents control the lighting characteristics and catalysts, esp. copper/chromium oxide, the lighting frequency. All constituents are powders of particle size 100 mu.

Method of burning a combustible substance by contact with combustion composition

Abstract: A combustion composition comprising a member selected from the group consisting of ferrocene, carborane, ferrocenyl and carboranyl derivatives; activated carbon; ammonium perchlorate; and aluminum powder. In operation, pellets or granules of the mixture are coated with calcium phosphate and applied to a combustible substrate.

Spherical ammonium perchlorate particle prodn - of controlled size by spraying into ammonia atmosphere, for rocket propellants

Abstract: Ammonium perchlorate (APC) can be with controlled particle size and shape by spraying aqueous perchloric acid into an NH3 rich atmos. The particle shape is controlled by the flow ratios in the spray chamber while the size is controlled by the droplet size. The perchloric acid droplet should have about twice thesize of the final APC crystal. There must always be a slight excess of NH3 in the spray chamber. APC is used in melt type solid rocket propellants.

Cocrystallization of ammonium perchlorate and stabilization of solid propellants

Abstract: A method of improving the thermal stability of double-base propellants containing ammonium perchlorate (AP) by cocrystallization of AP with resorcinol before formation of the propellant grain. AP is dissolved in a solution of liquid ammonia; resorcinol is added to the solution. After evaporation and drying the resulting cocrystals are ground and, in the conventional manner, incorporated into a propellant matrix.

A new look at AP/composite propellant combustion

Abstract: Some theoretical studies on the time-independent and oscillatory combustion of nonmetallized ammonium perchlorate (AP)/composite propellants are presented. A coherent and unified interpretation was made of the voluminous data available from experiments related to propellant combustion. Three fundamental hypotheses are introduced: the extent of propellant degradation at the vaporization step has to be specified through a scientific criterion; the condensed-phase degradation reaction of ammonium perchlorate to a vaporizable state is the overall rate-limiting step; gas-phase combustion rate is controlled by the mixing rate of fuel and oxidizer vapors. In the treatment of oscillatory combustion, the assumption of quasi-steady fluctuations in the gas phase is used to supplement these hypotheses.