Double-base smokeless powder

Double base smokeless powder was first produced by Alfred Nobel. Again we quote Urbanski (Ref 46a, p 530) ... 

With a focus on trace forensic detection of explosives, especially for use in counterterrorism and to counter narcotics investigations, Fetterolf et al. [75] evaluated the use of ion mobility-mass spectrometry for explosives determinations. In this, explosives residues were collected on a membrane filter by a special attachment on a household vacuum cleaner. Although subsequent thermal desorption and analysis required only 5 s, fimits of detection for most common explosives were as low as 200 pg. The persistence of explosives on hands and transfer to other surfaces were also examined as were post-blast residues of NG on fragments of improvised explosive devices constructed with double-based smokeless powder. Finally, postblast residue from C-4, Semtex, and other explosives was found by IMS analyses on items of forensic and evidentiary value. These few out of many examples demonstrate that mobihty spectrometers are well suited tools for laboratory and on-site investigations, before and after the use of explosives. 

Single base" smokeless powder, developed mainly in the United States, uses only nitrocellulose. "Double base" smokeless powder, developed in Europe, is a blend of nitrocellulose and nitroglycerine. "Cordite," a British development, consists of 65% NC, 30% NG, and 5% mineral jelly. The mineral jelly (a hydrocarbon material) functions as a coolant and produces substantial amounts of CO 2, CO, and H 2O gas to improve the propellant characteristics. "Triple base" smokeless powder, containing nitroguanidine as a third component with nitroglycerine and nitrocellulose is also manufactured. 

Fig. 8. Headspace SPME—GC/ECD of selected double-based smokeless powders.

Op of these with 100 parts of mixed nitric-sulfuric acid at about 7°(45°F). The resulting products had nitrogen contents about 18.3%, as compared with 18.67% theoretical. They are explosives with properties resembling those of inactive inositol hexanitrate. (The dextro- product is a solid, while the levo- product is a liquid). They are better gelatinizers than NG or NC and have been recommended as ingredients of double-base smokeless powder. They can also be used in dynamites or other commercial explosive mixtures in combination with NG or aromatic nitrocompounds. Crater has also claimed the use of 1H in non-headache dynamites (Ref 5)... 

The experiment with the MKIII ballistic mortar were run on smokeless powder because the powder is a problem to transport, there are three kinds of smokeless gun powder single base gun powder, double base gun powder and triple base gun powder. 

DuPont in the U.S. developed about 1909, a smokeless powder from cotton of relatively low nitrogen that was quite soluble in ether alcohol. A small amount of diphenylamine was used as a stabilizer. After forming the grains and removing the liquid, a coating of graphite was added to make the smokeless powder that was used in the U.S. Other double-base types contain about 25% nitroglycerin. Cotton lint for nitration has been replaced by purified wood cellulose. 

Cordite, the 2nd successful double-base propellant, was patented for the British Government by F. Abel J. Dewar and adopted as a military propint. It was Cordite Mark 1 or CSP[ (Cordite Smokeless Powder ) (See Vol 3 of Encycl, p C532-L also Ref 31a, p 295 Ref 44, p 246)... 

Double base A smokeless powder that contains both nitroglycerin and nitrocellulose. 

Smokeless powder A low explosive used in ammunition as a propellant, which can be single, double, or triple based. 

G-117-b (Rocket Powder). A double-base solventless extruded proplnt consisting of NC 50.0, NG 30.0, DNT 14.5, Ethyl Centralize 4.0 K sulfate 1.5% with carbon black 0.02 Pb stearate 0.40 added. This proplnt is smokeless, but has a high heat of expln which may give nozzle trap erosion Ref W.E. Campbell Jr L.H. Brown, Aerojet Report No 194(1946), p 12... 

Much attention is now paid to the mechanical properties of smokeless rocket powder [52], This stems from the requirement for physical integrity during manufacture, storage and firing. Any imperfection, such as a crack or deformation or a stress which may lead to a crack in the course of burning can cause serious ballistic malfunction. This defective behaviour is particularly liable to occur in large double base powder grains, hot extruded under pressure. 

Dinitrodiglycol is as toxic as nitroglycerine. It explodes at a temperature of 200°C developing a relatively small heat of detonation that amounts to 1070 kcal/kg. Advantage is taken of this property in the manufacture of flashless and non-errosive low calorific smokeless ( double base ) powder. 

During the last war a certain amount was manufactured in Germany for use as a component of smokeless (double-base) powder. The extent of production was limited, however, due to inadequate supplies of propionaldehyde. Trimethylol-methylmethane is produced in an analogous way to pentaerythritol by reacting propionaldehyde with formaldehyde ... 

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