Showing papers on "Ammonium perchlorate published in 1979"
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TL;DR: In this article, the effect of TMO catalysts on solid propellant burning and decomposition, oxidizer burning, and sandwich and condensed mixture combustion is discussed. But, the exact mechanism of the effect on the burning rate modification of composite solid propellants is not clear even today.
Abstract: Introduction T metal oxides (TMO) like Fe2O3, CuO, MnO2, CuCr2O4, etc., form a very popular group of catalysts for burning rate modification of composite solid propellants. Although it is well known that these oxides affect the decomposition characteristics of polymers and oxidizers like ammonium perchlorate (AP)' and potassium perchlorate, (KP) the exact mechanism of the effect on solid propellants is by no means clear even today. Much fragmentary literature is available on the effect of these oxides on propellant burning and decomposition, oxidizer burning and decomposition, and sandwich and condensed mixture combustion. It is the purpose of this review to bring the material together so that a comprehensive picture can be drawn of the mechanism of the action of these catalysts. It may be mentioned here that these oxides also catalyze hydrocarbon oxidation reactions by inducing free radical decomposition of hydroperoxides (formed by the contact of oxidizer and hydrocarbon).
91 citations
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15 Jan 1979
22 citations
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TL;DR: In this paper, the authors performed accelerated ageing studies for three composite propellant formulations, namely polystyrene (PS)/ ammonium perchlorate (AP), polymethylmethacrylate (PMMA)/AP and poly phenol formaldehyde (PPF)/AP, in the temperature range of 55-125°C.
Abstract: Accelerated ageing studies for three composite propellant formulations, namely polystyrene (PS)/ ammonium perchlorate (AP), polymethylmethacrylate (PMMA)/AP and poly phenol formaldehyde (PPF)/AP have been carried out in the temperature range of 55-125°C. Measurements of the ultimate compression strength (U c) and isothermal decomposition rate (TD rate) were monitored as a function of storage time and temperature. The change in U c was found to be linearly dependent on the change in TD rate irrespective of the propellant systems. Analysis of the results further revealed that the cause of ageing for both U c and burning rate (r) is the thermal decomposition of the propellant. The safe-life for the change in mechanical properties was found to be higher compared to the change in r for PS and PMMA based propellants.
13 citations
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12 citations
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TL;DR: In this paper, the burning rate of DINA is determined by the rate of heat evolution in the reaction zone of the condensed phase (the C-phase) as well as by the heat flux from the gas phase.
10 citations
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10 citations
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8 citations
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17 Apr 1979TL;DR: In this paper, metal/oxidant agglomerates for enhancement of propellant burningate are prepared from a finely divided metal (aluminum, boron, titanium, etc.), ammonium perchlorate, and a small quantity of the same binder material that goes into the manufacture of the propellant, such as, hydroxyl-terminated polybutadiene crosslinked with polyisocyanate.
Abstract: Preformed metal/oxidant agglomerates for enhancement of propellant burningate are prepared from a finely divided metal (aluminum, boron, titanium, etc.), ammonium perchlorate, and a small quantity of the same binder material that goes into the manufacture of the propellant, such as, hydroxyl-terminated polybutadiene crosslinked with a polyisocyanate. Additional ingredients can be incorporated into the agglomerates to bring about further enhancement of burning rate, such as, an ammonium perchlorate decomposition accelerator triphenylbismuthine, a carboranyl burning rate enhancer, iron oxide, etc. Agglomerates are prepared in a fluorinated and/or chlorinated hydrocarbon solvent in which the agglomerate formulation ingredients are insoluble. Any remaining solvent is then evaporated under reduced pressure and the agglomerates are subsequently cured. Optimum mesh size of the agglomerates is 300-500 micrometers. These agglomerates cause a major increase in the burning rate of solid propellants when incorporated therein in percentages of 1-5%.
8 citations
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10 May 1979
TL;DR: A composite solid propellant with a stable burning rate comprising ammonium perchlorate, a binder system of telomeric polybutadiene or copolymers of butadiene and acrylonitrile with terminal functional groups or functional groups distributed statistically along the chain, which are hardened by means of corresponding hardeners into rubber-elastic binders, finely pulverized, readily oxidizable metals and, optionally, inorganic fluorides, plasticizers and burning rate moderators, is presented as an agglomerate of larger particles having a particle size of between 100 μ
Abstract: A composite solid propellant with a stable burning rate comprising ammonium perchlorate, a binder system of telomeric polybutadiene or copolymers of butadiene and acrylonitrile with terminal functional groups or functional groups distributed statistically along the chain, which are hardened by means of corresponding hardeners into rubber-elastic binders, finely pulverized, readily oxidizable metals and, optionally, inorganic fluorides, plasticizers and burning rate moderators, wherein ammonium perchlorate together with one or more of said finely pulverized metals, as well as, optionally, said inorganic fluorides are present as an agglomerate of larger particles having a particle size of between 100 μm and 2,000 μm.
7 citations
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TL;DR: In this article, the effect of tri-and tetramethylammonium perchlorates (MAP-3 and MAP-4) on the burning rate of AP-based propellants has been determined at various pressures.
4 citations
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01 Jan 1979
TL;DR: In this article, stable state combustion modeling of composite solid propellants is discussed with emphasis on the BDP model and some revisions are considered with respect to the analysis of monomodal ammonium perchlorate/inert binder propellants: topics examined include continuity relations, surface area relations, characteristic surface dimension, flame heights and energy balance.
Abstract: Steady-state combustion modeling of composite solid propellants is discussed with emphasis on the Beckstead-Derr-Price (BDP) model. The BDP model and some revisions are considered with respect to the analysis of monomodal ammonium perchlorate/inert binder propellants: topics examined include continuity relations, surface area relations, characteristic surface dimension, flame heights, and energy balance. Application of the BDP model to more complicated propellants containing multiple active ingredients is described. These propellants include multimodal, mixed oxidizer, active binder, aluminized, catalyzed, and nitramine propellants. Example cases of modeling (with comparison to experimental data) are presented, and strengths and weaknesses of current modeling approaches are evaluated.
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TL;DR: In this article, it was shown that as the thermal decomposition of orthorhombic ammonium perchlorate proceeds there is an accumulation, in the solid, of hydrochloric and nitric acids, the concentrations of which increase up to 15% decomposition after which they decrease until they reach the original values.
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TL;DR: In this paper, products of conversion of the ferrous oxide catalyst collected from the burning region of an AP-PMMA mixture show significant aggregation of the catalyst, with large (40-50 μm) spherical particles having a metallic glitter.
Abstract: Products of conversion of the ferrous oxide catalyst collected from the burning region of an AP-PMMA mixture show the significant aggregation of the catalyst, with large (40–50 μm) spherical particles having a metallic glitter. Significant variations in the phase composition are observed, Fe3O4·γ-Fe2O3 solid solution and tetragonal and monoclinic Fe2O3 being formed.
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TL;DR: In this paper, the mass-spectrometric microprobing technique has been used for the first time in studies of the internal structure of a condensed system combustion front, which consists of moving a burning strand relative to a fixed microprobe with a constant speed exceeding that of combustion.
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TL;DR: In this article, a simplified theory for the ignition of ammonium perchlorate is proposed, which is derived from a unified theory that also explains the low-pressure deflagration limit as well as the steady deflagation.
Abstract: A simplified theory for the ignition of ammonium perchlorate is proposed, which is derived from a unified theory that also explains the low-pressure deflagration limit as well as the steady deflagration. The theory provides an approximate method of calculating the ignition delay and the minimum external he»t flux for a successful ignition, as functions of pressure and initial solid temperature. The ignition calculations show that there exists a pressure limit due to the weakness of the igniter strength, in addition to the low-pressure deflagration limit which is an inherent property of the solid independent of the igniter strength. The theory can be extended to other monopropellants for which exothermic reaction occurs only in the gas phase.