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Showing papers on "Ammonium perchlorate published in 1999"


Journal ArticleDOI
TL;DR: In this paper, a new computational technique (advanced isoconversional method) has been used to determine the dependence of the effective activation energy (Eα) on α for isothermal and nonisothermal TGA data.
Abstract: The methods of thermogravimetric analysis (TGA) and differential scanning calorimettry (DSC) have been used to study the thermal decomposition of ammonium perchlorate (AP). TGA curves obtained under both isothermal and nonisothermal conditions show a characteristic slowdown at the extents of conversion, α = 0.30−0.35. DSC demonstrates that in this region the process changes from an exothermic to an endothermic regime. The latter is ascribed to dissociative sublimation of AP. A new computational technique (advanced isoconversional method) has been used to determine the dependence of the effective activation energy (Eα) on α for isothermal and nonisothermal TGA data. At α > 0.1, the Eα dependencies obtained from isothermal and nonisothermal data are similar. By the completion of decomposition (α → 1) the activation energy for the isothermal and nonisothermal decomposition respectively rises to ∼110 and ∼130 kJ mol-1, which are assigned to the activation energy of sublimation. The initial decomposition (α → ...

240 citations


Journal ArticleDOI
TL;DR: This review is an attempt to consolidate the information available on the various issues pertaining to the use of ammonium nitrate as a solid propellant oxidizer in the area of propellants.

228 citations


Journal ArticleDOI
TL;DR: In this paper, a number of experimental techniques were developed for describing the characteristics of the CCPs as a function of the oxidizer particle size and pressure. But the results of these experiments were limited to the case of aluminized solid propellants.
Abstract: Experimental results are presented on the formation of condensed combustion products (CCPs) at the burning surface of aluminized solid propellants. A number of experimental techniques were developed for describing the characteristics of the CCPs as a function of the oxidizer particle size and pressure. The results of this investigation provide qualitative descriptions of the CCPs formed at the propellant burning surface as functions of oxidizer particle size and pressure. Nomenclature ak = oxidizing potential of gas mixture (mole share of oxidizing components in the mixture) D = diameter of agglomerate D43 = mass-medium diameter of agglomerates D AP = mass-medium diameter of ammonium perchlorate particles d = diameter of e ne oxide particle d HDO 43 = mass-medium diameter of e ne oxide particles Fm.D/ = mass function of agglomerate size distribution fm.D/ = mass function of agglomerate size distribution density fm.d/ = mass function of e ne oxide particle size distribution density P = pressure r = propellant burn rate T = temperature Zm = share of unburned metal in the agglomerates relative to the initial aluminum in the propellant Z a = share of initial metal in the propellant used to form the agglomerates as a whole Z HDO = share of initial metal in the propellant used to form the e ne oxide particles Z ox = share of initial metal in the propellant used to form oxide in the agglomerates ° = edge angle of wetting ´ = mass share of oxide in agglomerates

101 citations


Journal ArticleDOI
TL;DR: An ion chromatographic method was developed for the determination of low microgram/l levels of perchlorate in drinking and ground waters based on a Dionex IonPac AS11 column, a 100 mM hydroxide eluent, large loop injection, and suppressed conductivity detection.

64 citations


Journal ArticleDOI
TL;DR: In this article, the decomposition kinetics of the PBAN binder and three propellants based on ammonium perchlorate (AP) with PBAN, HTPB, or BAMO-AMMO binders were analyzed by an advanced isoconversional method.

49 citations


Journal ArticleDOI
TL;DR: In this article, a comparison of the properties of propellant containing solid and liquid ferrocene derivatives has been made with those containing Fe/sub 2/O/sub 3/ and n-butyl errocene, respectively.
Abstract: Some ferrocene derivatives like 2,4-dinitrophenylhydrazine derivative of acetyl ferrocene, 1-pyrrolidinylmethyl ferrocene, di-ter-butyl ferrocene and 1,3-diferrocenyl-l-butene (DFB) have been synthesised and characterised by infrared, nuclear magnetic resonance, ultraviolet, iron content, etc. To study the effect of their incorporation on performance, ammonium perchlorate/hydroxyl-terminated polybutadiene-based composite propellants containing these derivatives have been prepared and studied for burn rates, tensile strength and percentage elongation followed by their static test evaluation. A comparison of the properties of propellant containing solid and liquid ferrocene derivatives has been made with those containing Fe/sub 2/O/sub 3/ and n-butyl ferrocene, respectively. The data clearly indicates that these ferrocene derivatives are better than Fe/sub 2/O/sub 3/ and n-butyl errocene. Also, DFB is the best among these derivatives. Like composite propellants, DFB increases burn rate in fuel-rich propellants also.

28 citations


Patent
31 Mar 1999
TL;DR: An azide free gas producing composition (I), preferably for use in safety devices in motor vehicles, comprises (A) 20-60 wt.% fuel and (B) 40-80 wt% of an at least three component oxidising mixture as discussed by the authors.
Abstract: An azide free gas producing composition (I) , preferably for use in safety devices in motor vehicles comprises (A) 20-60 wt.% fuel and (B) 40-80 wt.% of an at least three component oxidising mixture. (A) comprises at least 95 wt.% of a guanidine compound and 0-5 wt.% of another fuel. (B) comprises 20-80 wt.% transition metal oxide, 0-50 wt.% basic copper nitrate, 1-15 wt.% metal chlorate, metal perchlorate and/or ammonium perchlorate and 1-15 wt% alkali nitrate and/or alkaline earth nitrate.

22 citations


Patent
10 Jun 1999
TL;DR: Improved non-azide gas generant compositions that may be used in a vehicle airbag system were presented in this article, where the new compositions overcome the problems of moisture and thermal cycling in a non-razide gas generator pellet through the use of at least two fuels selected from guanidine nitrate, nitroguanidine, triaminoguanidine nitrates, diaminoguanidine nitrates and monoguanidine ammonium perchlorate.
Abstract: Improved non-azide gas generant compositions (30) that may be used in a vehicle airbag system (10) The new compositions overcome the problems of moisture and thermal cycling in a non-azide gas generant pellet (30) through the use of at least two fuels selected from guanidine nitrate, nitroguanidine, triaminoguanidine nitrate, diaminoguanidine nitrate, and monoguanidine nitrate and an oxidizer system comprising mixtures of strontium nitrate, sodium nitrate, and ammonium perchlorate

20 citations


Journal ArticleDOI
TL;DR: In this paper, the effect of additives of metal oxides on the combustion of a composite solid propellant based on ammonium perchlorate is studied. And the potentials for affecting the composite solid liquid propellant via gas-phase oxidation-reduction reactions is indicated by the additive of organic sources of active species.
Abstract: Results of studies of the combustion of a composite solid propellant based on ammonium perchlorate are presented. The effect of additives of metal oxides is studied for the high and low-temperature decompositions, linear pyrolysis, and combustion of ammonium perchlorate, the decomposition of HClO4, isobutylene oxidation by oxygen and perchloric acid, and the combustion of propellants with various organic combustibles. It is shown that the efficiency of metal oxides in the reactions of oxidation of isobutylene and propellant combustion is related to the energy of the Me—O bond in the surface oxide layer or the enthalpy of formation of this bond. The extremal nature of the catalytic effect of metal oxides on the burning rate of the propellant is due to the small time of residence of the oxide particles in the zone of intense oxidation-reduction reactions. For this reason, the same additives of metal oxides has different effects on the combustion of the propellant with different organic, combustibles, and the most efficient catalyst can be chosen by a simplified algorithm. The potentials for affecting the composite solid propellant via gas-phase oxidation-reduction reactions is indicated by the effect of additives of organic sources of active species—amines and halides.

19 citations


Patent
08 Feb 1999
TL;DR: In this article, a non-explosive pyrotechnic material, which is auto-combustible at or near atmospheric pressure, comprises an energizing binder and ammonium perchlorate.
Abstract: Non-explosive pyrotechnic material, which is auto-combustible at or near atmospheric pressure, comprises an energizing binder and ammonium perchlorate. The material is auto-combustible after initiation by an electrical pulse. Non-explosive pyrotechnic material, which is auto-combustible at or near atmospheric pressure, comprises an energizing binder and ammonium perchlorate. The material has a thickness less than 500 microns or a mass less than 15 mg. The material is auto-combustible after initiation by an electrical pulse, P, such that 150 mW ≤ P ≤ 800 mW for a time, t, such that 20 ms ≤ t ≤ 600 ms. the material comprises: 25-80 wt.% energetic binder based on glycidyl polyazote (PAG), or poly-3,3-bis(azidomethyl)oxetane (BAMO), or polyester or polyether and at least one energizing plastifier; 10-70 wt.% ammonium perchlorate with grain size of 0.5-30 microns; and 0-45 wt.% at least one nitroamine. Independent claims are also included for energizing compound for making the material; and use of the material as micro-generator for gas or heat.

10 citations



Journal ArticleDOI
TL;DR: In this paper, the acidities and basicities of metal oxides were estimated thermogravimetrically by the method of adsorption of pyridine and formic acid as probe molecules, and the activation energies of the non-catalyzed and catalyzed pyrolysis of pure ammonium perchlorate (AP) were calculated from the TG results via the Coats-Redfern equation.
Abstract: Six metal oxide samples were prepared by calcination of the corresponding precursors at 500°C for 5 h in air and were characterized by IR and XRD analyses. Their surface areas were calculated by means of the BET method. The acidities and basicities of these metal oxides were estimated thermogravimetrically by the method of adsorption of pyridine and formic acid as probe molecules. The pyrolyses of pure ammonium perchlorate (AP) and of AP mixed with (10% w/w) metal oxide were studied, in a dynamic atmosphere of N2, by thermogravimetric analysis (TG) and derivative thermogravimetric analysis. A correlation was found between the catalytic activities of the metal oxides during the pyrolysis of AP, and their acidic-basic characters. The activation energies of the non-catalyzed and catalyzed pyrolysis of AP were calculated from the TG results via the Coats-Redfern equation.

Patent
01 Dec 1999
TL;DR: In this article, an azide-free gas-generating composition for use in safety devices for motor vehicles, comprising a fuel in a proportion of 20 to 60% by weight and consisting of one or more components, was presented.
Abstract: The present invention relates to an azide-free gas-generating composition, in particular for use in safety devices for motor vehicles, comprising a fuel in a proportion of 20 to 60% by weight and consisting of one or more components, and an oxidizer mixture in a proportion of 40 to 80% by weight and consisting of at least three components, each in relation to the total composition. In accordance with the invention, the fuel consists of a guanidine compound in a proportion of at least 95% by weight and a further fuel component in a proportion of 0 to less than 5% by weight, each in relation to the fuel, and the oxidizer mixture consists of one or more transition metal oxides in a proportion of 20 to 80% by weight, basic copper nitrate in a proportion of 0 to 50% by weight, metal chlorate, metal perchlorate, ammonium perchlorate or mixtures thereof in a proportion of 1 to 15% by weight and alkali metal nitrate, alkaline earth metal nitrate or mixtures thereof in a proportion of 1 to 15% by weight, each in relation to the oxidizer mixture.

Patent
23 Jul 1999
TL;DR: In this article, chlorate-free autoignition compositions are disclosed, and may be embodied in compositions comprised of (i) an azodiformamidine dinitrate (ADFD), a self-deflagrating, low ignition temperature fuel, (ii) an oxidizer (e.g., a perchlorate, nitrate or mixture thereof) and (iii) an ignition accelerator/augmentor, a metal or metal oxide powder).
Abstract: Chlorate-free autoignition compositions are disclosed, and may be embodied in compositions comprised of (i) an azodiformamidine dinitrate (ADFD), a self-deflagrating, low ignition temperature fuel, (ii) an oxidizer (e.g., a perchlorate, nitrate or mixture thereof) and (iii) an ignition accelerator/augmentor (e.g., a metal or metal oxide powder). One especially preferred solid AIP composition in accordance with the present invention includes ADFD, a mixture of ammonium perchlorate and sodium nitrate, an iron oxide powder and a binder, such as a poly(alkylene carbonate).

Patent
13 Dec 1999
TL;DR: In this article, a process for the biological purification of a water containing ammonium perchlorate is described, where aqueous ammonium-perchlorate solution is placed in contact, in a first, aerobic reactor, with an activated sludge in the presence of at least one source of mineral carbon and nutritional elements for the metabolism of the microorganisms.
Abstract: The invention relates to a process for the biological purification of a water containing ammonium perchlorate, characterized in that aqueous ammonium perchlorate solution is placed in contact, in a first, aerobic reactor, with an activated sludge in the presence of at least one source of mineral carbon and nutritional elements for the metabolism of the microorganisms, and then in that the liquid effluent leaving the first reactor is placed in contact, in a second, anoxic reactor, with an activated sludge, in the presence of at least one source of organic carbon and nutritional elements for the metabolism of the microorganisms. The process makes it possible to treat aqueous solutions containing very large amounts of ammonium perchlorate and to convert both the ammonium ions into molecular nitrogen and the perchlorate ions into chloride ions.

Journal ArticleDOI
TL;DR: In this article, the authors used triblock copolymers obtained from HTPB as additive to a solid propellant mixture based on HTPB with ammonium perchlorate (oxidiser), dioctyl adipate (plasticiser), and toluene diisocyanate (curing agent).
Abstract: Hydoxyl-terminated polybutadiene (HTPB), an important polymeric fuel binder for composite propellants, has been utilised to anchor tungsten hexachloride, a well-known metathesis catalyst. This anchored catalyst polymerises various monomers like phenylacetylene (PA) and norbornene (NBE) to give triblock copolymers via metathesis polymerisation. The triblock copolymers thus obtained are of the type polyA-block-polybutadiene-block-polyA and have been characterised by spectroscopic, thermal and gel permeation chromatographic techniques. As block copolymers have the characteristics of the individual polymers, they can be used as substitutes or additives in analogous polymeric formulations to improve the matrix properties. These triblock copolymers obtained from HTPB were employed as additives to a solid propellant mixture based on HTPB with ammonium perchlorate (oxidiser), dioctyl adipate (plasticiser) and toluene diisocyanate (curing agent). Burning rate studies of these propellant mixtures were conducted under various pressures to evaluate the individual ballistic nature. It was found that NBE-based additive imparts higher burning rate than the HTPB-based propellant. The effect of copper chromite as a burning rate modifier in this new formulation was also evaluated. The mechanical properties of the propellants were measured and compared to show the effect of triblock in the binder network. This paper mainly focuses on the synthesis and characterisation of the above triblock copolymers and burning rate studies of the propellants based on these polymers.

Journal ArticleDOI
TL;DR: In this paper, the card gap test was modified in order to apply it to solid rocket propellants and carried out to evaluate sensitivities against shock stimuli and found that the sensitivity was dominated by the oxidizer characteristics.
Abstract: Card gap test, which is standardized in Japan Explosives Society, was modified in order to apply it to solid rocket propellants and carried out to evaluate sensitivities against shock stimuli. Solid propellants tested here were mainly azide polymer composite propellants, which contained ammonium nitrate (AN) as a main oxidizer. Double base propellant, composed nitroglycerin and nitrocellulose (NC), and ammonium perchlorate (AP)-based composite propellants were also evaluated in order to compare with the azide polymer propellants. It is found that the sensitivity was dominated by the oxidizer characteristics. AP-and AN-based propellant had less sensitivity and HMX-based propellant showed higher sensitivity, and the adding of NC and TMETN were contributed to worse sensitive for the card gap test. Good relationship was obtained between the card gap sensitivity and the oxygen balance of propellants tested here.

Journal ArticleDOI
TL;DR: In this article, the effects of cure ratio, crosslinking density, ammonium perchlorate (AP) particle size, and other additives on the mechanical properties of azide polymer composite propellants were characterized.
Abstract: The effects of cure ratio, crosslinking density, ammonium perchlorate (AP) particle size, and other additives on the mechanical properties of azide polymer composite propellants were characterized. The equivalence ratio of 1.0 and IPDI/TPA=7/3 were effective on low temperature mechanical properties. Relatively high amount of plasticizer was required in BAMO/NMMO binder and preferred the equivalence ratio of 1.0 to retain itself in the three-dimensional binder matrix. Excellent elasticity was obtained at a temperature range between −20°C and 2°C and normal strain rate dependency was obtained at from 54°C to −20°C. Glass transition occurred at −30°C to −35°C in Sample 17. The increase in contact area between AP particle and binder and in bonding strength played an important role on the prevention of the propagation of crack around a boundary and, therefore, ϵm was increased with decrease of particle size. Almost exactly the same σm, however, was observed in whole temperature range with increment of 5% to 10% in ϵm.

Proceedings ArticleDOI
20 Jun 1999
TL;DR: In this article, the effect of pressure on the nature of extinguished propellant surfaces obtained is shown in scanning electron microscope micrographs using an SEM, it is possible to determine surface structures and compositions for comparison with propellant burning rate behavior.
Abstract: Specially formulated ammonium perchlorate HTPB propellants exhibit plateau behavior in their burning rates as pressure is increased. Several things affect the prominence of these plateaus, including binder curative, AP particle ratio, and presence of a ballistic modifier additive. The effect of pressure on the nature of extinguished propellant surfaces obtained is shown in scanning electron microscope micrographs. Using an SEM, it is possible to determine surface structures and compositions for comparison with propellant burning rate behavior. Four propellant formulations were tested over a range of pressure that bracketed the plateaus. The formulations varied in AP particle ratio, binder curative type, and the presence'of an additive.- The SEM analysis was able to correlate the burning rate behavior in terms of the appearance of the coarse AP particles relative to the surrounding matrix of fine AP and binder. Plateaus result from temporary degrees of suppressed burning of the fine AP component, due to binder melt layer interference.

Journal ArticleDOI
TL;DR: Thermal motion analysis indicates that the tert-butylammonium group and the perchlorate anion each librate with respect to the host, with amplitudes of 6.2 (4) and 11.4 (2) degrees, respectively.
Abstract: In the title complex, tert-butylammonium perchlorate-2,5,8,11,14,17-hexaoxatricyclo[16.8.0.0 20,25 ]hexacosa-1(26),18,20(25),21,23-pentaene-ethyl acetate-dichloro-methane (4/4/1/1), C 4 H 12 N + .C 20 H 26 O 6 .ClO 4 - .0.25C 4 -H 8 O 2 .0.25CH 2 Cl 2 , the tert-butylammonium cation binds to the macrocyclic host (Chemical Abstracts name: 2,3,5,6,8,9,11,12,14,15-decahydro-1,4,7,10,13,16-hexaoxanaphtho[2,3-b]cyclooctadecin) in the expected tripod arrangement, while the perchlorate anion links naphthyl groups in the crystal through C-H...O-Cl-O...H-C interactions. Thermal motion analysis indicates that the tert-butylammonium group and the perchlorate anion each librate with respect to the host, with amplitudes of 6.2 (4) and 11.4 (2)°, respectively.

Journal ArticleDOI
TL;DR: In this article, an experimental study is made of a chemical arc, a model layered system of solid components, between the end surfaces of which stationary combustion takes place, and a maximum mass combustion velocity is found to exist as a result of the transition from a low velocity (kinetic) to a high velocity reaction regime.
Abstract: An experimental study is made of a “chemical arc”, a model layered system of solid components, between the end surfaces of which stationary combustion takes place. The rates of combustion of the components in ammonium perchlorate-polyether, ammonium perchlorate-polyethylene, and ammonium perchlorate-butyl rubber systems with catalytic additives (diethyl ferrocene, epoxyethyl ferrocene, and iron oxide) are measured as functions of the distance between the components. A maximum mass combustion velocity is found to exist as a result of the transition from a low velocity (kinetic) to a high velocity reaction regime. The data are in qualitative agreement with theory. The mechanism by which the catalysts affect the combustion characteristics is analyzed.

Patent
27 Dec 1999
TL;DR: In this article, a new method for biological treatment of water containing ammonium perchlorate was proposed, which consisted of an aerobic reactor containing activated sludge containing nitrifying microorganisms in the presence of an inorganic carbon source and other nutrients.
Abstract: New method for biological treatment of water containing ammonium perchlorate. New method for biological treatment of water containing ammonium perchlorate. The method comprises: (a) an aerobic reactor containing activated sludge containing nitrifying microorganisms in the presence of an inorganic carbon source and other nutrients; and (b) an anoxic reactor containing activated sludge containing denitrifying microorganisms and perchlorate-reducing microorganisms in the presence of an inorganic carbon source and other nutrients.

Proceedings ArticleDOI
20 Jun 1999
TL;DR: Spontaneous Raman scattering spectroscopy was applied to fiames of the nitramines HMX, RDX, and nitramine-containing propellant XM39 and to counterflow flames of ammonium perchlorate with methane and ethylene.
Abstract: /-~-~ Spontaneous Raman scattering spectroscopy was applied to fiames of the nitramines HMX, RDX, and nitramine-containing propellant XM39 and to counterflow flames of ammonium perchlorate with methane and ethylene. The best results were obtained for the counter-flow flames and for XM39 for which long integration times without the problem of laser-induced breakdown were possible. Temperature was also obtained for XM39 by measuring Stokes and anti-Stokes Raman signals. Results for RDX near its surface was obtained, but due to insufficient spatial resolution, no profiles were measured. A large NO signal was seen with HCN still present. Limited results were obJained for H,MX in which laser-induced breakdown was a big problem as well as strong emissions of Na and CaOH , from sodium and calcium compound impurities.

27 Jul 1999
TL;DR: In this article, the oxidative thermal aging of a crosslinked hydroxyterminated polybutadiene (HTPB)/isophorone diisocyanate (IPDI) polyurethane rubber, commonly used as the polymeric binder matrix in solid rocket propellants, was studied at temperatures of RT to 125 C.
Abstract: The oxidative thermal aging of a crosslinked hydroxy-terminated polybutadiene (HTPB)/isophorone diisocyanate (IPDI) polyurethane rubber, commonly used as the polymeric binder matrix in solid rocket propellants, was studied at temperatures of RT to 125 C. We investigate changes in tensile elongation, mechanical hardening, polymer network properties, density, O{sub 2} permeation and molecular chain dynamics using a range of techniques including solvent swelling, detailed modulus profiling and NMR relaxation measurements. Using extensive data superposition and highly sensitive oxygen consumption measurements, we critically evaluate the Arrhenius methodology, which normally assumes a linear extrapolation of high temperature aging data. Significant curvature in the Arrhenius diagram of these oxidation rates was observed similar to previous results found for other rubber materials. Preliminary gel/network properties suggest that crosslinking is the dominant process at higher temperatures. We also assess the importance of other constituents such as ammonium perchlorate or aluminum powder in the propellant formulation.

Journal ArticleDOI
01 May 1999
TL;DR: In this article, an energetic polymeric binder based on azido hydroxy terminated polybutadiene (AHTPB) was proposed, prepared and characterized, and the performance of these propellant formulations was deduced through a computer program.
Abstract: Composite solid rocket propellants based on hydroxy terminated polybutadiene (HTPB) have become the workhorse propellants in solid rocket motors world-wide. It was reported that polymers containing azide groups exhibit an interesting feature. On pyrolysis or combustion they liberate extra heat due to the scission of the azide bond which is highly exothermic. In this paper energetic polymeric binder based on azido hydroxy terminated polybutadiene (AHTPB) was proposed, prepared and characterized. The synthesis was started by brominating the commercial hydroxy terminated polybutadiene (HTPB), followed by its refluxing with sodium azide for about 30 hours. The investigated propellant formulations were based on mixtures of the prepared energetic binder (AHTPB) (13%) with different nitrogen content, ammonium perchlorate (71%) and Aluminum (16%).The performance of these propellant formulations was deduced through a computer program. Also, the effect of nitrogen content variation of the polymeric fuel binder on the specific impulse and the adiabatic flame temperature was investigated.

Proceedings ArticleDOI
20 Jun 1999
TL;DR: A non-steady model for the combustion of ammonium======perchlorate composite propellants has been developed in this article in order to be incorporated into a comprehensive gas-dynamics model of solid rocket motor flow fields.
Abstract: A non-steady model for the combustion of ammonium perchlorate composite propellants has been developed in order to be incorporated into a comprehensive gasdynamics model of solid rocket motor flow fields. The model including the heterogeneous combustion and turbulence mechanisms is applied to nonlinear combustion instability analyses. This paper describes the essential mechanisms and features of the model and discusses the methodology of non-steady calculations of the combustion instabilities of solid rocket motors.