Oxidizer hypergolic

If a fuel ignites spontaneously on coming in contact with an oxidizer(hypergollic propellant) there is no need for any ignition devices... 

HAZARD RISK Combustible when exposed to heat or flame can react vigorously with oxidizers hypergolic reaction with concentrated nitric acid decomposition emits acrid smoke and irritating fumes NFPA Code H 3 F 1 R 0. 

The gas has no practical application as an expl. It is of importance, however, as an additive to N204 to depress the fr p of this biproplnt hypergolic oxidizer (Ref 7). It is also... 

Hypergolic reaction systems have been proposed (Refs 46 73) for 5.56mm ammo, specifically triethylaluminum (TEA) together with inorganic oxidizers. This system is self-igniting in air, but is compatible with some nitrates, chlorates and perchlorates... 

To describe hypergolic heating, Anderson and Brown (A10) proposed a theoretical model based upon spontaneous exothermic heterogeneous reactions between the reactive oxidizer and a condensed phase at the gas-solid interface. In these studies, the least complex case was considered, i.e., the one in which the solid phase is instantaneously exposed to a stagnant (nonflowing) gaseous oxidizer environment. This situation can be achieved experimentally provided the sample to be tested is suddenly injected into the desired environment in a manner designed to minimize gas flow. 

Parametric studies showed that mass diffusion in the gas phase could be neglected under most conditions. The calculations also show that the selection of the hypergolic combination (i.e., the gaseous oxidizer and the propellant system) fixes all of the parameters except the initial temperature and the oxidizer concentration. A general solution of the model shows that the ignition-delay time is approximately rated to the gaseous oxidizer concentration by the relation... 

A powerful reducing agent and fuel, hypergolic with many oxidants such as dinitrogen tetraoxide or hydrogen peroxide. 

Noble, P. et al., Am. Inst. Aeron. Astronaut. J.. 1963,1, 395-397 Hexanitroethane is a powerful oxidant and hypergolic with dimethylhydrazine or other strong organic bases. 

Oxidation of alkanethiols to alkanesulfonic acids with excess cone, acid as usually described is potentially hazardous, the exotherm often causing ignition of the thiol. A modified method involving oxidation under nitrogen and at temperatures 1-2 C above the m.p. of the thiol is safer and gives purer products [1]. Technical butanethiol (containing 28% of propane- and 7% of pentane-thiols) is hypergolic with 96% acid [2], Oxidation of several thiols to the sulfonic acids by addition to stirred cone, acid had been effected normally, but when 2 new... 

Hypergolic behavior is characterized by immediate, spontaneous ignition of an oxidation reaction upon mixing of two or more substances. 

Blends of perchloryl fluoride with halogen fluorides are homogeneous and stable. When these are used as storable liquid oxidizers for rocket propulsion, the halogen fluoride usually confers hypergolicity, increased density, and lowered vapor pressure whereas the perchloryl fluoride provides oxygen needed for efficient combustion of carbon in the fuel or of certain metal additives. The mixtures are thermally stable and their... 

Hypergolic Oxidizer and Fuel Mixtures. A list of oxidizers and fuels which are hypergolic follows RFNA with aniline (Ref 7) N2H4 (Refs 8 9) H2 (Ref 10) toluene (Ref 11) diethylenetriamine (Ref 8) MMH (Ref 8) ... 

M. Kilpatrick L.L. Baker, Jr, A study of fast reactions in fuel-oxidant systems, FifthSymp Comb, Reinhold, NY, (1955) 26) S.A. Masier et al, Hypergolic ignition of light hydrocarbon fuels with fluorine-oxygen (FLOX) mixtures, ... 

Vast numbers of fuels may be combined with the above oxidizers to form biproplnts. Many hypergolic biproplnt systems are listed in this Vol, pp H254-L to H259-R, under Hypergolic Propellants. The foregoing tabulation (Table 72, p 317 of Ref 23) lists several common biproplnts... 

Intermixing of gelled N204 UDMH (unsym-dimethylhydrazine) results in a fire if large surface areas of gelled fuel oxidizer come in contact. The fire is similar to.that which occurs when two hypergolic proplnts are... 

The requirements for selecting a fuel and oxidizer as a liquid bipropellant system are usually a compromise between the demands of the vehicle system, the propulsion system, and the propellants themselves. The vehicle and propulsion system will determine performance levels, physical property requirements, thermal requirements, auxiliary combustion requirements, degree of storability and package-ability, hypergolicity, etc. The final propellant selection must not only satisfy such requirements but is also dictated by thermochemical demands which the fuel and oxidizer make on each other. Frequently, specifically required properties are achieved through the use of chemical additives and/or propellant blending. 

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