Showing papers on "Ammonium perchlorate published in 1990"

Proton-conducting polymer electrolyte. I. The polyethylene oxide+NH4ClO4 system

Abstract: Proton transport in solution-cast films of polyethylene oxide (PEO) complexed with ammonium perchlorate (NH4ClO4) has been established using optical microscopy, XRD, DTA, IR, coulometry, transient ionic current and electrical conductivity studies. The solubility of NH4ClO4 in PEO is found to be limited to a maximum concentration NH4+/EO ratio of 0.167. The highest conductivity ( approximately 1.05*10-5 S cm-1) is for the film with NH4+/EO=0.02-0.1. The H+ ion transference number, tH+, and mobility, mu H+, are 0.85 and 1.7*10-4 cm2 V-1 s-1, respectively. The movement of ClO4- ions also contributes slightly to the overall charge transport.

Burning rate characteristics of GAP propellants

Abstract: The burning rate and flame structure of glycidyl azide polymer (GAP)-based composite propellants were examined in order to obtain a wide spectrum of burning rates. Crystalline fine particles of ammonium perchlorate, cyclotetramethylene tetranitramine, or triaminoguanidine nitrate, were mixed within GAP to formulate GAP propellants. Since GAP is an energetic self-sustaining combustible polymer, the burning rate characteristics of GAP propellants appeared to be fundamentally different from those of conventional composite propellants. Measured results indicate that the burning rate, pressure exponent, temperature sensitivity, and flame structure depend largely on the concentration of the crystalline additives. The observed burning rate characteristics were correlated with the concentration of the crystalline particles.

Thermal analysis of ammonium perchlorate +polystyrene +additive mixtures I

Abstract: The thermolysis of ammonium perchlorate (AP) and AP/polystyrene propellants was investigated with carboxylates of copper as additives. The rate of burning was found to be enhanced considerably. TG and ignition delay studies demonstrated that the high-temperature decomposition of AP is enhanced enormously by these additives, whereas the low-temperature decomposition remains unaffected. It is suggested that the main species catalysing the rate of burning or AP decomposition is CuO. Analysis showed that the increase in the rate of burning is controlled by the catalysis of AP decomposition.

Effects of different additives on the thermal decomposition of ammonium perchlorate

Abstract: IR spectral investigations on ammonium perchlorate (AP) in the presence of varying amounts of ammonium permanganate (APm) and 2% by weight of different rare earth oxide additives were made over the temperature range 25–290°. Heating and spectral scanning were done simultaneously and the peak intensity was presumed to be proportional to the amount of undecomposed AP. Presence of 10% APm lowered the temperature of AP decomposition from 200 to 110° and increased the rate by several folds. Mixed oxide produced as a result of deflagration of APm are considered catalyzing the process. In the presence of rare earth oxides additives, the NH 4 + stretching peak intensity decreased considerably, the extent followed the trend Gd2O3 > MnO2 > Nd2O3 > Pr2O3 > Dy2O3 > Y2O3 > La2O3 > virgin AP. An electron transfer mechanism is envisaged to explain the results.

FTIR spectroscopic study on the Interaction between Ammonium Perchlorate and Bonding Agents

Abstract: The interaction between ammonium perchlorate and bonding agents has been investigated by means of Fourier transform infrared spectroscopy (FTIR). The analysis results endorse that the interfacial bonding force is hydrogen bond for aziridine type compounds and ionic bond for alkylene polyamine derivatives, respectively.

Phase-stabilization of ammonium nitrate by zinc diammine complexes

Abstract: A phase-stable, oxidizer-grade zinc diammine complex stabilized ammonium nitrate that retains its phase-stability, has a minimum hygroscopicity and cure interference, is prepared by dissolving an anhydrous zinc diammine complex, which may be either the sulfate, perchlorate or nitrate, in dry molten ammonium nitrate. The complex is best prepared in a separate step by melting a 3/1 molar mixture of ammonium nitrate with zinc oxide which produces the zinc diammine dinitrate complex contaminated with the water of the reaction. The melt is dried by driving off the water. First by simple boiling, and the final traces by means of purging with dry air or nitrogen gas. The ammonia lost in this drying operation is exactly replenished by purging with anhydrous ammonia gas. The sulfate complex is obtained by co-dissolving an essentially stoichiometric quantity of ammonium sulfate in either the melt of the complex or the bulk of the molten ammonium nitrate. The perchlorate complex is prepared similarly by co-dissolving a stoichiometric quantity of ammonium perchlorate in the molten ammonium nitrate.

Novel kinetic scheme for the ammonium perchlorate gas phase

Abstract: A novel gas-phase kinetic scheme for ammonium perchlorate (AP) deflagration involving 22 reactions among 18 species is developed The kinetic scheme is based on a study of the effect of initial conditions on the solution of the differential equations of adiabatic constant-pressure combustion kinetics The existence of condensed-phase reaction products providesalternate pathways for the consumption of NH3 and HCIOl produced by gas-phase dissociation of AP Theoretically obtained temperature-time profiles of the novel scheme do not change when the conventional reaction pathways are included, indicatingthat the novel scheme is a substantially faster rate process The new scheme does not involve the species CIO, which has long been considered a critical component of the AP gas phase and which is included in the conventional reaction pathwaysThe new scheme develops faster overall reaction rates, steeper temperature-time profiles, and in a deflagration model will result in higher heat-transfer rates from gas phase to the condensed phase

Characteristics of Porous Ammonium Perchlorate and propellants containing same

Abstract: Une methode utilisant un lit fluidise a 230 o C, a permis de preparer du perchlorate d'ammonium poreux. Par un examen au microscope electronique a balayage, on a determine la structure geometrique de ce perchlorate poreux. On a egalement determine les proprietes physiques et mecaniques des propergols composites a base de perchlorate d'ammonium poreux. Du fait de la diffusion du liant dans les pores du perchlorate le pouvoir d'allongement diminue

Combustion mechanisms of nitramine-based propellants with additives

Abstract: Propellants containing HMX and an energetic binder have a very pressure sensitive burning rate law. Modifications of the burning rate and of the pressure exponent may be obtained by adding lead salts or ammonium perchlorate (AP) to the propellant. In the first case, the additive effect is related to the possibility for the binder to produce efficient finely divided carbon near the combustion surface. In the second case, the effect results from an interaction between AP flame oxygen and binder flame products. This interaction is observed between 20 and 300 bars. Its importance depends on the AP particle size. In parallel with this experimental study, an interpretative combustion model has been developed. This model is based on a sequential combustion concept and allows one to correlate the experimental results and especially the dependence of the burning rate on the HMX mass ratio. Nomenclature A = pre-exponential factor cp = heat capacity D = diameter E = activation energy / = mass fraction M - mass NJ = number of particle of size / in a unit volume | Qc = heat balance in the condensed phase, cal/g rb = burning rate V = volume £ = volumic fraction p = specific mass 0 = heat flux transferred from gas to condensed phase Subscripts

High performance space motor solid propellants

Abstract: A family of high performance, space motor, solid propellants based on polyglycidyl nitrate elastomer binder, ammonium perchlorate oxidizer and beryllium or beryllium hydride fuel which do not require the presence of plasticizers. A high performance, space motor, solid propellant based on a polyglycidyl nitrate elastomer binder, ammonium perchlorate or hydroxy ammonium perchlorate and beryllium or beryllium hydride optimizes performance at low solids levels.

Inhibition reaction of SrCO3 on the burning rate of ammonium perchlorate propellants

Abstract: The buring rate of ammonium perchlorate (AP) composite propellants is decreased significantly by the addition of SrCO3 without increasing the pressure exponent of burning rate. Results of microthermocouple measurements indicate that the burning surface temperature is increased from 700 K to 970 K by the addition of SrCO3, although the heat release rate in the gas phase is remained unchanged. DTA (differential thermal analysis) and TG (thermogravimetry) experiments were also carried out in order to determine the role of SrCO3 in the decomposition process of AP. The AP decomposition temperature is increased from 590 K to 620 K by the addition of SrCO3. The results of analysis show that the reduction of the burning rate is caused by the increased AP decomposition temperature.

Diaminoglyoxime and diaminofurazan in propellants based on ammonium perchlorate

Abstract: Solid propellants in which the oxidizer is a perchlorate are improved by the inclusion of diaminoglyoxime or diaminofurazan in the propellant compositions.

A rapid non‐aqueous titrimetric estimation of ammonium perchlorate in pyrotechnic compositions

Abstract: Pour l'analyse, le reactif utilise est l'hydroxyde de tetrabutylammonium et le solvant utilise est le DMF, le DMSO ou la pyridine; l'analyse se fait en utilisant le bleu de thymol comme indicateur ou une methode potentiometrique

Destruction of propellant components in supercritical water

Abstract: Supercritical water oxidation is an innovative, relatively low-temperature process that can give high destruction efficiencies for a wide variety of hazardous chemical wastes. It takes place in a water medium with added oxidant above the critical point of water. In this paper we present preliminary results for the destruction of propellant components in supercritical water without added oxidant. Reactions of ammonium perchlorate and nitromethane are examined using a flow reactor made of Hastelloy C276 operated at temperatures as high as 580{degree}C at pressures near 38.7 MPa. (5500 psig). Over 99.8% of the ammonium perchlorate is destroyed in less than 15 seconds at 500{degree}C. The reaction produces primarily chloride ion, nitrous oxide, and oxygen. A small amount of the nitrogen is converted into nitrate ion and nitrite ion. No reaction is detected in 180 seconds at temperatures below 400{degree}C. For nitromethane, over 99% is destroyed at 500{degree}C within 30 seconds. The reaction produces negligible amounts of nitrate and nitrite. Effluents from both ammonium perchlorate and nitromethane experiments were analyzed for metal ions that could results from corrosion of the reactor.

Burning Rate of a Trimodal Composite Rocket Propellant

Abstract: Some new perceptions in the field of composite propellants are considered. The effects of trimodal oxidizer distribution on the burning rate of composite propellants are considered. It is note that reducing the oxidizer particles in the presence of depressors reduces the burning rate of these propellants. In the formulation of the experimental approach, modern and effective methods of experimental design with the application of extremevertices design were used. SOLID composite propellant is a heterogenous mixture of crystalline oxidizer, polymer as a binder and fuel, metallic powder, burning-rate modifiers, and other additives regulating physico-chemical properties required to meet specific design objectives. For high-energy composite propellants, ammonium perchlorate (AP) is the preferred oxidizer. The polymeric binder, which acts as a fuel in the combustion process, accounts for the mechanical properties of a solid propellant charge. Metal powder improves the energetic characteristics of a propellant by increasing the combustion temperature. Burning-rate modifiers serve to increase (catalysts) and reduce (depressors) burning rates. The most frequently used catalysts are metal oxides and solid and liquid metaboric organic compounds. For the burning-rate depressors, fluorides, oxides, and carbonates of lithium, calcium, strontium, and barium are used. The specific composition is a function of the physical and chemical properties required for each particular missile. This complexity of composite rocket propellant compositions poses a difficult problem to research people in creating and defining compositions having specified properties. Renie et al., 1 Cohen and Strand,2 and Beckstead et al. 3 have analyzed the effect of particle size of ammonium perchlorate on the burning rate. Results were obtained for both unimodal and bimodal propellants with oxidizer particle size ranging from ultrafine 0.7 /xm to coarse 400 fim. For unimodal propellants, it was determined that the burning rate was higher for the smaller oxidizer sizes as would be expected. For the bimodal distributions, the results were consistent with those that could be inferred from the unimodal results. Specifically, the burning rates were strong functions of the coarse-to-fine ratio and the mean diameter of the fine fraction. Miller4 investigated the effects of ammonium perchlorate size distribution in a series of nonaluminized propellants. Burning rates were measured using cured strands and correlated to a characteristic particle size of the ammonium perchlorate. Horton and Rice5 analyzed the effects of different compositions (ammonium perchlorate particle size, copper chromite, and lithium fluoride) on the oscillatory combustion of a polybutyl-acrylic acid propellant. The objective of the current research is to extend these results by investigating the effect of trimodal oxidizer distributions on the burning rate, and the effect of lithium fluoride as a burning-rate depressor. Specifically, statistically designed

Burn Rate Mechanisms. Volume 2. A Model for Ammonium Nitrate Propellant Combustion

Abstract: : When the space shuttle is launched, each Solid Rocket Motor (SRM) booster generates approximately 100 tons of HCI in the exhaust. Thus, with the two boosters, over 200 tons of HCI is generated from each space shuttle launch. The HCI presents several potential problems. The HOI provides nucleation sites for moisture in the air - with the result being the condensed, hydrated form of hydrochloric acid (HCI.H2O). The resultant acid cloud results in a very visible cloud which through further condensation can result in acid rain. The acid rain is obviously detrimental to both plant and animal life dependent on the concentration levels it achieves as it reaches the ground. In addition, at higher elevations, the HOI can react with the protective layer of ozone causing a degradation of some of the ozone. The HO comes from the AR (ammonium perchlorate) which is the oxidizer in the solid propellant for the 5PM boosters. The SRM propellant contains approximately 70% AP which generates slightly more than 21 weight percent HG in the exhaust gases. For these reasons it is desirable to find a replacement for the AP to eliminate the HCI in the rocket exhaust.

Polymer temperature sensing element

Abstract: PURPOSE:To detect temperature with high precision at a high temperature by adding the preset quantity of a heat-resistant plasticizer, perchlorate, a stabilizer, and calcium carbonate to vinyl chloride resin 100 pts.wt. CONSTITUTION:A composition material added with a heat-resistant plasticizer 25-100 pts.wt., perchlorate of a fourth-grade nitrogen containing compound 0.1-5 pts.wt., a stabilizer 5-30 pts.wt., and calcium carbonate 10-100 pts.wt. to vinyl chloride resin or a mixture 100 pts.wt. of vinyl chloride resin and chlorinated polyolefin is mainly used to form a polymer temperature sensing element with excellent copper deterioration characteristic. The commercial vinyl chloride resin is used, and the chlorinated polyolefin is used to improve the moldability of vinyl chloride. The commercial heat-resistant plasticizer with the molecular weight of 450 or above is preferable. Fourth-grade ammonium perchlorate is preferable for the fourth-grade nitrogen containing compound. The stabilizer ordinarily used for the stabilization of vinyl chloride resin is sufficient.

Positive type resist using electron beams

Abstract: PURPOSE:To enhance sensitivity and resolution of a resist by incorporating a specified compound in a specified polymer. CONSTITUTION:This resist is formed by adding quaternary ammonium perchlorate (B) of formula II, each of R1 - R4 being 1 - 20 C alkyl, such as tetra-n-butyl ammonium perchlorate, to a cyclohexyl 2-cyanoacrylate polymer (A) of formula I having a molecular weight of 10 - 10 . This resist can be developed by a solvent mixture of 2-ethoxyethanol and 2-propanol and the like in a short time without leaving any residual film.

Fuel mixture, useful e.g. to operate ship machines, comprises propellant, oxidative agent, sea water and a compound, which combines with magnesium in the sea water, to prevent the formation of magnesium oxide during combustion

Abstract: Fuel mixture (I) for ship machines, comprises a mixture of a simple propellant, an oxidative agent, sea water and a compound, which combines with a partial or total amount of magnesium contained in the sea water, to prevent the formation of magnesium oxide during combustion. Independent claims are included for: (1) an oxidative agent useful in the fuel mixture comprising the compound, which is mixed with an aqueous solution of hydroxyl ammonium perchlorate; (2) preparing the oxidative agent comprising mixing perchloric acid and hydroxyl amine in a given pH, where the end-pH value of 0.1M solution, after adding the phosphoric acid is 3-4; and (3) the operation of the ship machine containing a combustion chamber comprising introducing (I) into the combustion chamber.