Showing papers on "Ammonium perchlorate published in 1991"
TL;DR: In this paper, the combustion behavior of B/MA/AP/HTPB fuel rich propellants containing different coated boron particles was studied with several diagnostic facilities such as windowed strand burner, CO2 laser ignition facility, rapid depressurization quenched device, thermal analyzer and micromotor static test.
Abstract: Combustion behavior of B/MA/AP/HTPB fuel rich propellants containing different coated boron particles was studied with several diagnostic facilities such as windowed strand burner, CO2 laser ignition facility, rapid depressurization quenched device, thermal analyzer and micromotor static test. Materials selected for boron coating include LiF, Viton A and silane. Baseline propellant containing uncoated boron was also studied for comparison Results from windowed strand burner and static test show that LiF-propellant exhibits the most remarkable overall behavior. Ignition study indicates that LiF-propellant gives the shortest while Viton A-propellant gives the longest ignition time under the same heat flux. Moreover, mechanisms were proposed to elucidate the experimental results and the observed combustion phenomena.
56 citations
TL;DR: In this article, the authors examined the radiative effects in aluminized propellants by embedding optical fibers and micro-thermocouples in propellants to measure radiative and conductive feedback.
37 citations
TL;DR: In this article, the catalytic effects of doped or mixed CuO-Cr2O3 oxides on the thermal decomposition of ammonium perchlorate (AP) were investigated by using DTA, electrical conductivity and X-ray diffraction techniques.
Abstract: The catalytic effects of doped or mixed CuO-Cr2O3 oxides on the thermal decomposition of ammonium perchlorate (AP) were investigated by using DTA, electrical conductivity and X-ray diffraction techniques. The results obtained revealed that the decrease in the defect electron of CuO catalyst doped with 1 at.% Cr3+ inhibited its activity, while the opposite effect was observed when Cr2O3 was doped with 1 at.% Cu2+. On increase of the concentrations of both oxides, the catalyst containing 70 at.% Cr3+ was found to be the most active during the decomposition of AP. The existence of CuCr2O4 at this ratio was demonstrated by X-ray diffraction. The activity of this spinel was explained on the basis of a hopping mechanism between Cr3+/Cr4+ active sites. Finally, the activation energies of different decomposition stages of AP alone and mixed with catalysts were calculated.
31 citations
TL;DR: Friction sensitivity of ammonium perchlorate (AP) composite propellants has been studied experimentally by means of thermal analysis and micro-thermocouple techniques as mentioned in this paper, and the results of friction sensitivity test show that the samples are sensitized when the concentration of catalysis which are used for high burning rate propellants is increased.
Abstract: Friction sensitivity of ammonium perchlorate (AP) composite propellants has been studied experimentally by means of thermal analysis and micro-thermocouple techniques. Several types of catalysts were mixed with AP in order to examine the effect of the reactivity on the sensitivity. The results of friction sensitivity test show that the samples are sensitized when the concentration of catalysis which are used for high burning rate propellants is increased. Metal contents within the catalysts tend to give some effects on the friction sensitivity. Based on the results of the temperature profile measurements in combustion waves, it is found that the friction sensitivity is correlated with the burning surface temperature of the propellants. The catalysts which accclerate the AP decomposition are responsible for the friction sensitivity but not for the fallhammer sensitivity.
17 citations
TL;DR: In this article, the role of crystal defects in forming hot spots during shock loading of large, optical quality, pure single crystals of ammonium perchlorate (AP) was investigated.
Abstract: The purpose of this work is to perform a microscopic-scale study of the role that crystal defects have in forming hot spots during shock loading of large, optical quality, pure single crystals of ammonium perchlorate (AP). The crystals were immersed in mineral oil at various distances from a detonator that provided the shock. The small explosive donor permitted recovery of the crystals for quantitative chemical analysis of decomposition and microindentation hardness testing. Hardness testing was also performed on an unshocked crystal to determine 1) the slip systems associated with primary and secondary deformation in accommodating the indenter and 2) the crack propagation directions at the surface as well as into the crystal. High-speed photographs of the shock-loaded crystals showed slip and cracking systems identified by hardness testing. Some of the systems were luminous. In addition, when a crystal with a large indentation was shocked near its reaction threshold, significant light appeared in the vicinity of the identation following shock passage. As such, preferred chemical reactivity in AP has been associated with its deformation systems and the presence of large strain centers.
17 citations
TL;DR: In this article, the flammability limits and ballistic properties of composite fuel-rich propellants were studied experimentally, using PBAN/AP propellant formulations, and higher pressure and AP contents as well as smaller AP particle size were found to promote sustained combustion and to increase burning rate.
Abstract: The flammability limits and ballistic properties of composite fuel-rich propellants were studied experimentally, using PBAN/AP propellant formulations. Higher pressure and AP contents as well as smaller AP particle size were found to promote sustained combustion and to increase burning rate. The addition of potassium perchlorate (KP) in place of AP increased the burning rate pressure exponent from about 0.3 to over 0.7 at optimum conditions. Ferric oxide and copper chromite catalysts caused an increase of the burning rate by a factor of 2, while the addition of aluminum powder at the expense of the fuel binder was found to have a remarkable effect on the burning rate with a maximum increase of as high as 5-fold.
13 citations
Patent•
17 May 1991TL;DR: Ammonium perchlorate is produced by oxidizing a solution of chloric acid substantially free of ionic impurities, and then introducing gaseous ammonia or an ammonium hydroxide solution into the crystallizing zone to produce ammonium per-chlorate crystals as discussed by the authors.
Abstract: Ammonium perchlorate is produced a process which comprises: (a) oxidizing a solution of chloric acid substantially free of ionic impurities, (b) introducing gaseous ammonia or an ammonium hydroxide solution into the crystallizing zone to produce ammonium perchlorate crystals, wherein the aqueous solution of perchloric acid and/or the ammonium hydroxide solution is in droplet form. High purity ammonium perchlorate crystals can now be produced directly which are free of transition metals, sulfates and phosphates, as well as substantially free of other ionic impurities including alkali metals, chlorate and chloride.
12 citations
TL;DR: In this article, the authors used a CO 2 laser at relatively low heat flux and sub-atmospheric pressures to simulate space environments and also simplify our understanding of the nature of ignition phenomena.
11 citations
TL;DR: In this article, the effects of several liquid burning rate catalysts on rheological properties of composite rocket propellants on the basis of hydroxy-terminated polybutadiene as a binder and ammonium perchlorate as an oxidizer have been examined.
Abstract: Effects of several liquid burning rate catalysts on rheological properties of composite rocket propellants on the basis of hydroxy-terminated polybutadiene as a binder and ammonium perchlorate as an oxidizer have been examined. Theoretical explanation of the observed effects of liquid catalysts on certain rheological properties of the mentioned propellants are given. Laboratory procedures for synthesis of used catalysts are described. The results of physico-chemical characterization of synthesized catalyst are also presented.
9 citations
Patent•
05 Jun 1991
TL;DR: In this paper, the subject composition is obtained by adding (A) 0.001-10 pts. of at least one of silicate salt compounds of the formula (M is an alkaline earth metal, aluminum: (a) is 3/2, when M is aluminum; (n) is 1-5; (m) is an arbitrary positive integer).
Abstract: PURPOSE:To obtain the subject composition good in heat resistance, colorability and moldability and useful for automotive interiors, etc., by adding a silicate salt, a metal perchlorate salt, ammonium perchlorate salt, a specific hydrotalcite, etc., and a beta-diketone compound to a vinyl chloride resin. CONSTITUTION:The objective resin composition is obtained by adding (A) 0.001-10 pts.wt. of at least one of silicate salt compounds of the formula (M is an alkaline earth metal, aluminum: (a) is 1, when M is an alkaline earth metal, and (a) is 3/2, when M is aluminum; (n) is 1-5; (m) is an arbitrary positive integer) (e.g. calcium silicate), (B) 0.001-10 pts.wt. of a metal perchlorate (e.g. barium perchlorate), ammonium perchlorate, perchloric acid-treated hydrotalcite or a perchloric acid-treated silicate salt, and (C) 0.001-10 pts.wt. of at least one of beta-diketone compounds (e.g. dibenzoylmethane) to 100 pts.wt. of a vinyl chloride resin. which is used for powder molding and is excellent in heat resistance, thermal againg resistance, colorability and moldability.
8 citations
TL;DR: Differential scanning calorimetry and differential thermogravimetry (DTG) measurements showed that the thermal decomposition temperature of porous residual ammonium perchlorate is up to 50°C lower than that of normal ammoniumperchlorate as discussed by the authors.
TL;DR: In this article, Tetracycline (TC) is used to offset the trouble in curing process brought about by Zirconium powder addition, however, Zr powder would incur the acceleration of urethance forming reaction so as to make the pot life of the HTPB/AP propellant dough shorter.
Abstract: Typical reduced smoke type composite propellants mainly composed of hydroxyl-terminated polybutadiene (HTPB) and ammonium perchlorate (AP) have a drawback that these propellant grains have a high response function of the burning rate to cause acoustic pressure oscillation. The addition of a small fraction (0.5% ∼ 1.2wt%) of zirconium (Zr) or zirconium oxide powders to propellant compositions has been known to be effective for suppressing such a combustion instability. It is also notified, however, Zr powder would incur the acceleration of urethance forming reaction so as to make the pot life of the HTPB/AP propellant dough shorter. This paper reports that tetracycline (TC) is available to offset such a trouble in curing process brought about by Zr powder addition.
Patent•
30 Oct 1991
TL;DR: In this article, an image forming material for sublimation transfer is formed by holding a clayey mineral composite wherein a quaternary ammonium ion or an ion ion is bonded between the clayy mineral layers by ion exchange and quaternaries ammonium perchlorate or quaternally phosphonium per chlorate is held as an intercalary compound on a substrate.
Abstract: PURPOSE:To obtain an image forming material for sublimation transfer excellent in sensitivity and fixing properties by holding a clayey mineral composite wherein a quaternary ammonium ion or a quaternary phosphonium ion are bonded between clayey mineral layers by ion exchange and quaternary ammonium perchlorate or quaternary phosphonium perchlorate is held as an intercalary compound on a substrate. CONSTITUTION:An image forming material for sublimation transfer is formed by holding a clayey mineral composite wherein a quaternary ammonium ion or a quaternary phosphonium ion is bonded between clayey mineral layers by ion exchange and quaternary ammonium perchlorate or quaternary phosphonium perchlorate is held as an intercalary compound on a substrate. When the intercalation between the clayey mineral layers having a laminar structure is utilized as a fixing mechanism and the decomposition heating due to the thermal stimulation of org. perchlorate held between the clayey mineral layers is utilized as a sensitizing mechanism, desired effect is obtained and sensitivity and fixing properties can be improved.
Patent•
20 Feb 1991
TL;DR: In this article, a stabilizer for halogen-containing resins consisting of an alkali metal perchlorate (preferably lithium perchlorates) or quaternary ammonium per-chlorate) and polyethylene glycol and polypropylene glycol or a polymer containing at least one thereof is presented.
Abstract: PURPOSE:To obtain a stabilizer for halogen-containing resins, consisting essentially of a perchlorate and polyether-based polymer and capable of imparting excellent stability to deterioration by light and heat and antistatic effects to the halogen-containing resins. CONSTITUTION:A stabilizer for halogen-containing resins consisting essentially of (A) an alkali metal perchlorate (preferably lithium perchlorate) or quaternary ammonium perchlorate) and (B) a polymer composed of polyethylene glycol and/or polypropylene glycol or a polymer containing at least one thereof (preferably a block copolymer of the polyethylene glycol and polypropylene glycol). A halogen-containing resin (e.g. vinyl chloride resin) in an amount of 100 pts.wt. is blended with the resultant stabilizer so as to provide respective 0.001-5 pts.wt. components (A) and (B). Thereby, a stabilized electrically conductive halogen- containing resin composition is obtained.
01 Jan 1991
TL;DR: In this article, the influence of using chemical reagents to modify the powder surfaces upon propellant characteristics (burning rates, rheology, etc.) is described, and the results indicate that neither single component antistatic agents (such as 1831, 1631) or single component moisture-proof materials and assistant-friction materials can inhibit coalgulation, but surface agents can inhibit coagulation.
Abstract: Ultra-fine ammonium perchlorate (UFAP, d=0.5-l μm) is directly produced by a new dry method. In order to keep the UFAP from coagulation during storage, various surface modifications of UFAP have been studied. The results indicate that neither single—component antistatic agents (such as 1831, 1631) or single—component moisture-proof materials and assistant-friction materials prevent coalgulation, but surface agents can inhibit coagulation. The influence of using chemical reagents to modify the powder surfaces upon propellant characteristics (burning rates, rheology, etc.) is described.
01 Jan 1991
TL;DR: In this article, experimental data on the effect of catalytic additives on the combustion characteristics of ammonium nitrate and perchlorate and the explosives of different classes were presented. But the results were limited to the case of a constant pressure bomb with a broad range of pressure from the lower limit up to 1000 atmospheres.
Abstract: This work presents experimental data on the effect of catalytic additives on the combustion characteristics of ammonium nitrate and perchlorate and the explosives of different classes. Burning rates are determined photographically in a constant pressure bomb within a broad range of pressure: from the lower limit up to 1000 atmospheres.
01 Jan 1991
TL;DR: The surface characteristics of the particles of the ultra-fine ammonium perchlorate in the liquid media and the influences of various types and the concentrations of additives on the surface characteristics, stability, coagulation etc. have been studied as discussed by the authors.
Abstract: During the production of the ultra—fine ammonium perchlorate and the determination of the particle size of the ultra—fine ammonium perchlorate, a suspension colloid containing liquid media and ultra—fine ammonium perchlorate is prepared. Because of surface charge characteristics and other forces between the particles, the particles of the ultra—fine ammonium perchlorate in the liquid media are not stable and tend to coagulate and precipitate. The surface characteristics of the particles of the ultra—fine ammonium perchlorate in the liquid media and the influences of various types and the concentrations of additives on the surface characteristics, stability, coagulation etc. have been studied. It is demonstrated that the surface characteristics of the particles can be modified, thus improving the stability and dispersion characteristics.