Pyrocollodion cotton

Nitrocellulose powders can be classified into semicolloidal powders made of two kinds of nitrocellulose (insoluble and soluble in the solvent—ether and alcohol), almost fully colloidal, made of pyrocollodion cotton (highly soluble in ether-alcohol) and Schultze type powders with a very low content of colloidal nitrocellulose and containing inorganic salts. The Schultze nitrocellulose powders are now of little significance and very little used, so they will be discussed only briefly. 

In some countries (e.g. in the U.S.S.R. and in the U.S.A.) thick strips (for cannon powders) may be cut immediately after the extrusion of the tubes. This is possible only when pyrocollodion cotton is used for the manufacture of the powder since it is easily soluble and requires only a small amount of solvent (about 80% by weight of nitrocellulose). After cutting the powder is subjected to predrying. When... 

Davis [12] reports the following figures characteristic of the hygroscopicity of pyrocollodion cotton containing various substances ... 

Pyrocollodion cotton with 5% hydrocellulose 10% crystalline DNX 10% DNX oil 10% crystalline DNT 20% crystalline DNT 25% crystalline DNT... 

Davis [25] found that non-volatile solvents vary in their capacity for gelatinizing nitrocellulose, depending on the liquid in which they are dissolved. The following data show the gelatinizing power of pyrocollodion cotton (Table 185). The figures indicate the parts of non-volatile solvent required for the complete gelatinization of 100 parts of pyrocollodion cotton. 

Ability to completely gelatinize pyrocollodion cotton OF VARIOUS NON-VOLATILE SOLVENTS, ACCORDING TO DAVIS [25]... 

Partly soluble in ether-alcohol Pyroxyline, pyrocollodion cotton, pyrocellulose 1.653... 

Pirokollodion (Pyrocollodion). A single-base proplnt contg NC of 12.45% N invented by D.I. Mendeleev in 1891. This proplnt served as a prototype for the Pyrocellulose single-base proplnt introduced in the US in 1895 by Ber-nadou and adopted by the Navy. Pyrocellulose, or simply Pyro is based on NC of about 12.6% N. See Collodion Cotton or Pyroxylin and Pyrocellulose, Pyro or Pyrocotton in Vol 2, C103-R to C106-L... 

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