Rocket propellants oxidizer

Grade C, Type II is typical of Hquid oxygen used as a rocket propellant oxidizer. Particulate content is limited because of the critical clearances found in mechanical parts of the rocket engine. In addition to water, acetylene and methane are limited because, on long standing, oxygen evaporation could cause concentration of these combustible contaminants to reach hazardous levels. 

This section is introduced with the interesting report in a patent that the thermal stability of N,AT-dinitramide salts [M+[N(N02)]" in which M+ is a nitrogen-containing cation, is improved by mixing the salt with small amounts of a base of type 1 [107]. N,AT-Dinitramide salts are used as explosives and as rocket propellant oxidizers. 

Polymer-based rocket propellants are generally referred to as composite propellants, and often identified by the elastomer used, eg, urethane propellants or carboxy- (CTPB) or hydroxy- (HTPB) terrninated polybutadiene propellants. The cross-linked polymers act as a viscoelastic matrix to provide mechanical strength, and as a fuel to react with the oxidizers present. Ammonium perchlorate and ammonium nitrate are the most common oxidizers used nitramines such as HMX or RDX may be added to react with the fuels and increase the impulse produced. Many other substances may be added including metallic fuels, plasticizers, stabilizers, catalysts, ballistic modifiers, and bonding agents. Typical components are Hsted in Table 1. 

Oxidizers. The characteristics of the oxidizer affect the baUistic and mechanical properties of a composite propellant as well as the processibihty. Oxidizers are selected to provide the best combination of available oxygen, high density, low heat of formation, and maximum gas volume in reaction with binders. Increases in oxidizer content increase the density, the adiabatic flame temperature, and the specific impulse of a propellant up to a maximum. The most commonly used inorganic oxidizer in both composite and nitroceUulose-based rocket propellant is ammonium perchlorate. The primary combustion products of an ammonium perchlorate propellant and a polymeric binder containing C, H, and O are CO2, H2, O2, and HCl. Ammonium nitrate has been used in slow burning propellants, and where a smokeless exhaust is requited. Nitramines such as RDX and HMX have also been used where maximum energy is essential. 

Oxidizing Properties. Nitric acid is a powerful oxidizing agent (electron acceptor) that reacts violentiy with many organic materials (eg, turpentine, charcoal, and charred sawdust) (19,20). The concentrated acid may react explosively with ethanol (qv). Such oxidizing properties have had military appHcation nitric acid is used with certain organics, eg, furfuryl alcohol and aniline, as rocket propellant (see Explosives AND PROPELLANTS). 

Group 15 (VA) Perchlorates. Nitrogen perchlorates have been used as oxidizers in rocket propellants. Hydrazine perchlorate [13762-80-6] NH2NH2CIO4, and hydrazine diperchlorate, CIO4NH2NH2CIO4, have been investigated as oxidizers for propellant systems (60). Anhydrous salts can be... 

Sohd rocket propellants represent a very special case of a particulate composite ia which inorganic propellant particles, about 75% by volume, are bound ia an organic matrix such as polyurethane. An essential requirement is that the composite be uniform to promote a steady burning reaction (1). Further examples of particulate composites are those with metal matrices and iaclude cermets, which consist of ceramic particles ia a metal matrix, and dispersion hardened alloys, ia which the particles may be metal oxides or intermetallic compounds with smaller diameters and lower volume fractions than those ia cermets (1). The general nature of particulate reinforcement is such that the resulting composite material is macroscopicaHy isotropic. 

Rocket propellant is a mixture of combustible substances that is burned inside the combustion chamber of a rocket engine. Burning is the chemical process of decomposition and oxidation of the propellant. The resulting highly heated and compressed gas (propulsive mass) is ejected from a combustion chamber and facilitates propulsion—movement of the aggregate attached to the rocket engine. In physi-... 

Although modern chemistry allows development of even more effective rocket propellants, energy efficiency is not the only consideration factor. For example, fluorine and its derivatives arc better oxidizers than oxygen, but their extreme toxicity make them environmentally dangerous. The same concerns prevent the use of beryllium hydride—an excellent fuel that combines high density with the energy efficiency comparable to liquid hydrogen. 

Nitrogen Oxides as Rocket Fuel Oxidants Including The Theoretical Performances of Propellant Systems Employing Nitrogen Tetroxide , JPL PR No 9-23, Cal Inst Tech, Proj No TU2-1,... 

A Small but important daSS of fOi mUlatiOnS comprises the Composite Solid Rocket Propellants. Composites typically contain a major amount of an oxidizer such as AP or HMX, a metal powder such as Al, a binder which is one or another type of rubber (or double-base), and up to a dozen trace ingredients such as catalysts, stabilizers, etc. There are literally hundreds of formulations, all to a degree similar and the choice comes down to specific missions, economics, and special requirements Loading of End Items. The blends and formulations described above may be loaded into their hardware in the plant where they are made, or they may be shipped to another plant for Load/... 

See Dibenzoyl peroxide Lithium tetrahydroaluminate Hydrazine Oxidants REDOX REACTIONS ROCKET PROPELLANTS... 

See Dichlorine oxide Dicyanogen Fluorine Halogens Oxygen (Liquid) Liquefied gases Ozone Dicyanogen ROCKET PROPELLANTS... 

This oxidant-fuel system was evaluated as a rocket propellant combination. 

Monomethylhydrazine is a clear, colorless liquid used extensively in military applications as a missile and rocket propellant, in chemical power sources, and as a solvent and chemical intermediate. Upon contact with strong oxidizers (e.g., hydrogen peroxide, nitrogen tetroxide, chlorine, fluorine) spontaneous ignition may occur. 

Used industrially as a fluorinating agent and as an oxidizer in rocket propellant systems. This material is on the ITF-25 low threat list. 

Uses Laboratory reagent for detecting double bonds in organic compounds oxidizer in rocket propellants monopropellant increase octane rating for diesel fuel. 

Eluorine nitrate (FNO ) is a strong oxidizing gas or liquid. In the liquid state it explodes by shock or friction. It is used as an oxidizer for rocket propellant fuels. 

The compound cerium oxide (either Ce Oj or CeO ) is used to coat the inside of ovens because it was discovered that food cannot stick to oven walls that are coated with cerium oxide. Cerium compounds are used as electrodes in high-intensity lamps and film projectors used by the motion picture industry. Cerium is also used in the manufacturing and polishing of high-refraction lenses for cameras and telescopes and in the manufacture of incandescent lantern mantles. It additionally acts as a chemical reagent, a misch metal, and a chemical catalyst. Cerium halides are an important component of the textile and photographic industries, as an additive to other metals, and in automobile catalytic converters. Cerium is also used as an alloy to make special steel for jet engines, solid-state instruments, and rocket propellants. 

Combustion of powdered aluminum with steam is a potentially attractive propulsion system for torpedoes, because of the very high-energy density (energy per unit volume) that can be achieved. Since the oxidizer can be taken from the environment, on-board storage is required only for the aluminum propellant. A study of potential torpedo propellant/oxidizer combinations including Al, Zr, Mg, and Li metals, hydrocarbon fuels, and typical solid rocket propellants, and... 

Potassium perchlorate (KP KCIO4) is a weU-known oxidizer, used as an oxidizer component of black powder. Since KP produces potassium oxides and condensed products, the high molecular mass Mg of the combustion products is not favorable for its use as an oxidizer in rocket propellants. A mixture of 75 % KP with 25 % asphalt pitch was used as a rocket propellant named Galcit, which was the original prototype of a composite propellant in the 1940 s. Potassium chlorate (KCIO3) is also a crystalline oxidizer, and although it has a lower oxygen content compared... 

Though the oxidation potentials of potassium nitrate (KN KNO3) and sodium nitrate (SN NaN03) are high, both metal nitrates generate combustion products of high Mg, Thus, the specific impulse becomes low when KN or SN is used in a rocket propellant KN and SN are used as major ingredients of explosives and in pyrotechnics. KN is a weU-known material as a major component of black powder. 

Since rocket propellants are composed of oxidizers and fuels, the specific impulseis essenhally determined by the stoichiometry of these chemical ingredients. Ni-tramines such as RDX and HMX are high-energy materials and no oxidizers or fuels are required to gain further increased specific impulse. AP composite propellants composed of AP particles and a polymeric binder are formulated so as to make the mixture ratio as close as possible to their stoichiometric ratio. As shown in Fig. 4.14, the maximum is obtained at about p(0.89), with the remaining fraction being HTPB used as a fuel component. 

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