Rockets oxidisers

The third type of propellent explosive, the composite type, is a more recent development, the purpose of which is to provide rocket propellants of increased thrust, compared with the ordinary varieties. Composite propellants are based on an oxidising solid, commonly a perchlorate, together with an organic binder which both acts as fuel and gives adequate mechanical strength to the mixture. The search for even more energetic compositions continues, but because of the military importance of the... 

Polymers which give mouldable propellants are mixed with the oxidiser in a similar manner, but the product is usually worked mechanically between rolls and evacuated to remove air bubbles. The powder is then moulded by pressure into the metal casing. Alternatively, such plastics can give a propellant which can be extruded into charges which are afterwards cut and machined to suitable shape. The Rocket Propulsion Establishment at Westcott has used ammonium perchlorate and polyisobutene to produce a propellant of putty-like consistency. 

A stoicheiometric mixture with sucrose ignites at 159°C, and has been evaluated as a rocket propellant [1], Dry powdered mixtures with glucose containing above 50% of chlorate explode under a hammer-blow [2], Pyrotechnic mixtures with lactose begin to react exothermally at about 200°C, when the lactose melts, and carbon is formed. This is then oxidised by the chlorate at about 340° C. The mechanism was studied by DTA [3],... 

The survey of hazards and safety procedures involved in handling rocket fuels and oxidisers includes liquid hydrogen, pentaborane, fluorine, chlorine trifluoride, ozone, dinitrogen tetraoxide, hydrazine, methyl hydrazine and 1,1-dimethyl hydrazine [1]. The later volume [2] is a bargain compendium of five NFPA publications ... 

When black powder is used to propel rockets it is classed as a composite propellant (where the fuel and oxidiser are intimately mixed) and forms part of a rocket motor in which the powder is compressed to form a monolithic single grain inside a combustion chamber as shown in Figure 3.1. As well as gunpowder, the composite propellant mix will contain a binder which is used to improve the cohesion of the ingredients. Binders form a distinct phase and tend to reduce the sensitiveness of the propellant to shock and impact. When based on organic materials, as is normally the case, they will serve as part of the fuel component also. 

In the case of a rocket, the chemical reaction between the fuels and oxidisers in the propellant forces product gases through the nozzle at a certain momentum, while the momentum of the rocket increases in the opposite direction. 

Aluminium particles are made with diameters in the range of 20 to 200 nm, with a protective shell of aluminium oxide about 4 nm thick and, mixed with a suitable oxidising agent, are used for rocket propulsion fuels. 

Oxygen can be extracted from the atmosphere by liquefaction and fractional distillation. The liquid boils at 183°C (90 K) and is dangerous when mixed with combustible materials. The compressed ags is used in metallurgy (e.g., steel-making) and the liquid as an oxidiser for rocket propulsion. 

The rocket fuel blend of cardanol (20 parts), norbornadiene (40 parts) and carene (40 parts) exhibit synergistic spontaneous ignition with an oxidiser such as red fuming nitric acid (ref. 275) and copolymerisation has been found to be one of the pre-ignition reactions (ref. 276). 

When black powder is used to propel rockets it is classed as propellant (where the fuel and oxidiser are intimately mixed) and forms part of a rocket motor in which the powder is compressed to form a monolithic single grain inside a combustion chamber as shown in Figure 3.1. 

Two types of rocket motor propellants were used, namely a composite (C) and a doublebase (DB) type. The C-type propellants consisted of heterogeneous grains where the fuel and oxidiser were held together in a synthetic rubber matrix. The DB-types had homogeneous grains containing small amoimts of dispersed additives. There were 12 C-type and 6 DB-type rocket motor propellants. 

Used as an oxidiser in rocket propellants, as an explosive and for the detn. of double bonds in organic compds. and for detn. of sulfur compds. d 1.623. Mp 13.8°. Bp 126°, Bpi4 9 30°. Steam-volatile. 

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