Double-base propellants rocket

Nitroglycerine is one of the most important and most frequently used components of explosive materials together with nitroglycol, it is the major component of gelatinous industrial explosives. In combination with nitrocellulose and stabilizers, it is the principal component of powders, gun propellants and smokeless solid rocket propellants (- double base propellants). 

Single and Double-Base Propellants. Early solid rocket propellants were based on processing methods similar to that used in the mbber industry, with propellants extmded into the desired grain configuration. Propellants... 

Solvcniless powder in Japan Flashless charges and flashless powders Smokeless powder with penthrite Smokeless powders containing nitroaliphatic compounds Smokeless powders for rockets Cast double base propellants Technology of casting Powder casting process Slurrying process... 

Ammonium perchlorate (AP) is the crystalline oxidizer most widely used to formulate composite propellants for rockets. Unlike double-base propellants, AP composite propellants are not used as gun propellants because the combustion products of AP composite propellants generate a high mass fraction of hydrogen chloride (HC1), which acts to oxidize and erode the interior surface of gun barrels. 

Rocket Propellants. SoHd rocket propellants are mostly based on chemically cross-linked polymeric elastomers to provide the mechanical properties required in launchings and the environmental conditions experienced in storage, shipment, and handling (see Elastomers, synthetic). Double-and triple-based nitrocellulose propellants are also employed as rocket propellants. 

Solventless Extrusion Process. The solvendess process for making double-base propellants has been used ia the United States primarily for the manufacture of rocket propellant grains having web thickness from ca 1.35 to 15 cm and for thin-sheet mortar (M8) propellant. The process offers such advantages as minimal dimensional changes after extmsion, the elimination of the drying process, and better long-term baUistic uniformity because there is no loss of volatile solvent. The composition and properties of typical double-base solvent extmded rocket and mortar propellant are Hsted ia Table... 

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/... 

The proplnts described above are in the realm of prior art and depict those NC proplnts with low smoke potential that are used primarily as gun proplnts. Recent research and development work has been concentrated on creating both gun proplnts and rocket proplnts with reduced smoke output in order to foil countermeasures. Lavitt (Ref 76) found that the concurrent use of optimum proportions of lead stearate and sodium barbiturate in double-base proplnts resulted in a marked reduction in smoke output. This was attributed to the synergistic interaction of the two salts to produce more complete oxidation of the exhaust products. The importance of using the optimum ratio of the two catalysts is demonstrated by the higher smoke values shown in Table 4 for Propellants 105, 106 and 107, when compared to other... 

Double-base propellants, 10 725 Double-base rocket propellants, 10 726... 

M55 rockets pose the greatest storage risk because they contain approximately 20 pounds of M28 propellant, a double-base propellant composed of nitroglycerine, nitrocellulose, plasticizers, a bum-rate modifier, and a stabilizer. The exact composition is given in Table 1-4. The propellant slowly decomposes exother-... 

Most composite propellants in wide use today use ammonium perchlorate as the oxidizer component. While such propellants benefit from high specific impulse and a lower vulnerability than double-base propellants based on nitroglycerine, they have a significant environmental impact, the exhaust fumes being rich in corrosive hydrogen chloride leading to acid rain after the launch of missiles/rockets. 

Fig.4.n Rocket flight trajectories assisted by (a) an NC-NG double-base propellant and (b) an aluminized AP composite propellant. 

These double-base propellants are best known as smokeless propellants used in guns and rockets. Two major ingredients are used to formulate the double-base propellant grains NG and NG. As covered in Section 4.2.2, NG is a nitrate ester characterized by -O-NO2 groups, and is known as a high explosive. Since NG is a liquid at room temperature, it is absorbed by NG and serves to gelatinize the latter to form... 

The chemical compositions and thermochemical properties of representative NC-NG and NC-TMETN double-base propellants are compared in Table 4.9. Though the NC/NG mass ratio of 0.80 is much smaller than the NC/TMETM mass ratio of 1.38, the combustion performance in terms of Tf and Mg is seen to be similar, and 0 is 109 kmol K kg for both propellants. In the case of rocket motor operation, Igp and pj, are also approximately equivalent for both propellants. 

Double-base propellants containing azide polymers are termed nitro-azide polymer propellants. DEP used as a plasticizer of double-base propellants is replaced with azide polymers in order to increase energy density. The compatibility of GAP prepolymer with NG serves to suitably desensitize the mechanical sensitivity of NG and gives superior mechanical properties in the formulation of rocket propellant grains. 

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