Single bases powders

As single base powders have been developed particularly in the U.S.A., their method of manufacture may be described as illustrating the principles involved. British practice is similar but often with omission of the macaroni pressing stage. 

Calorimetric values of single base powders lie in the range 4000-3000 J g 1 and for double base 5200-3000 J g-1 for ammunition or down to 1750 J g 1 for use in power cartridges. 

In Russia, Mendeleyev [12] worked out a method for the manufacture of smokeless powder from pyrocellulose, i.e. relatively high-nitrated (12.5% N) nitrocellulose soluble in a mixture of ether and alcohol. In 1892 the manufacture of this powder was started for naval guns. Nitrocellulose powder of this type was soon adopted for military purposes in the U.S.A., where nitrocellulose powder became known as single base powder . 

J. Taylor [27] drew up the following table of the heat of explosive decomposition, the gas volume and rate of burning of British nitroglycerine (double base) and American nitrocellulose (single base) powders (Table 166). 

In Anglo-Saxon countries nitrocellulose powders are known as single base powders, i.e. made of only one explosive component. 

Heat test at 134.5°C. This heat test is in use in the U.S.A. A sample of 2.5 g of nitrocellulose or nitrocellulose powder ( single base powder ) is kept in a long test tube in a constant temperature bath regulated to 134.5+0.5°C. A band of methyl violet (rosaniline acetate with crystal violet) test paper is kept over the surface of the sample. The test paper should not change to salmon colour before 30 min and no visible N02 vapours should be detected before 45 min. 

TLP (Ger). Treibladungspulver (gun propint). The following suffix designations, eg, TLP/A indicate A—E=single base powder A=nitro-cellulose powder D=DNT added F-M=double base powder F=NC-NG G=NC-diglycol dinitrate K=ball powder N-P=triple base powders V-W=porous powders... 

Diphenylamine is the most common stabilizer especially in single-based powders. It has been suggested that diphenylamine is not a good stabilizer for double-based propellants as it may hydrolyze NG.59 2-Nitrodi-phenylamine is used for double- and triple-based propellants. 

Sicherheitszundschnure = safety fuses 276 Silberacetylid 285 Silberazid 286 Silbercarbid 285 Silberfulminat 287 silver acetylide 285 silver azide 286 silver carbide 285 silvered vessel test 286 silver fulminate 287 single bases powders 287 SiNCO = qas qeneratinq propellant (german) 288... 

A-E = single base powder A nitrocellulose powder D DNT added F-M = double base powders F = nitrocellulose nitroglycerine G = nitrocellulose-diglycol dinitrate K = ball powder N-P = triple base powders V-W = porous powders (german) TMEMT = trimethylenetrinitrosamine 71... 

A method, developed by Bergmann and Junk in 1904, for testing the chemical stability of nitrocellulose it was also subsequently employed for testing single-base powders. The test tube, which contains the specimen being tested, and which is equipped with a cup attachment, is heated at 132 °C= 270.4°F for two hours (nitrocellulose) or five hours (single base powders). At the end of the heating period the sample is extracted with water, and the test tube filled to the 50-ml mark with the water in the cup. The solution is filtered, and the content of nitrous oxides is determined by the Schulze-Tiemann method on an aliquot of the filtrate. 

The propellant which has exclusively been used for a long time in conventional military weapons is the smokeless (or, more accurately, low-smoke) powder. According to its composition, it can be classified as single-base powders (e.g., nitrocellulose powder), doublebase powders (e.g., nitroglycerine powder) and triple-base powders (e.g., nitrocellulose + nitroglycerine (or diglycol dinitrate) + nitroguanidine powders). 

Properties Have greater potential than the single base powders, and a smaller weight of charge may be used to attain a specified muzzle velocity. More corrosive than single-base powders. 

For Properties and Uses, see Guncotton, Pyrocotton, Collodion Cotton, Smokeless Powder, Single-Base Powder, Double-Base Powder, Ball Powder. 

See Propellants, Single-Base Powders, Double-Base Powders, I. M. R. Powder, Sporting Powder, Nitrocellulose, Pyrocotton, Guncotton, Ball Powder, P1,12 27. See also... 

---