Gun cotton = Nitrocellulose

The first successhil attempt to make textile fibers from plant cellulose can be traced to George Audemars (1). In 1855 he dissolved the nitrated form of cellulose in ether and alcohol and discovered that fibers were formed as the dope was drawn into the air. These soft strong nitrocellulose fibers could be woven into fabrics but had a serious drawback they were explosive, nitrated cellulose being the basis of gun-cotton (see Cellulose esters, inorganic esters). 

The most widely used inorganic ester of cellulose is cellulose nitrate (CN), also called nitrocellulose or gun cotton. Celluloid is produced from a mixture of CN and camphor. It was first made in 1833 when cellulose-containing linen, paper, or sawdust was reacted with concentrated nitric acid. It was the first synthetic cellulose product that was recognized. Initially, CN was used as a military explosive and improvements allowed the manufacture of smokeless powder. A representation of CN is given in structure 9.7. 

Nitric acid Nitric acid Nitro starch Nitro starch Nitrocellulose Mitrated cornstarch Improvised explosive mixture Nitrated cellulose, Gun cotton, CeUulosetrinitrate... 

Nitrocellulose (NC) Main component in smokeless powder, i.e., gun cotton. Nitroglycerin (NG) Explosive material, originally the basis for dynamite. Oleander extract A poison. 

They are made of nitrocellulose, which is the same highly combustible material used to make gun cotton as well as flash paper (see page 318). 

Nitrocellulose or gun cotton was discovered by Braconnot (France, 1833) and patented by Schonbein (1846) (Fig. 1). It is speculated that in order to determine whether the action of nitric acid was a reaction or merely a sorption into fibrous material, Sobrero (1846) treated glycerin, a liquid, with nitric acid and found a true reaction took place. Hence, nitrocellulose and nitroglycerin were discovered within a decade of each other, but neither found widespread use until the 1860 s when methods of stabilizing them were devised. Between 1865 and 1868, Abel patented improved preparations of nitrocellulose. He found that pulping allowed impurities, such as residual acid, to be more easily washed out by "poaching" and resulted in improved stability. The Abel stability test is named after him[5]. 

The chemistry of explosives was very active at that time as nitroglycerine was introduced. Nitrocellulose, known as gun cotton, was produced by the direct nitration of cellulose. The discovery and the use of nitrocellulose were associated with the names of two scientists, Schonbein and Bottger. 

The quantity of the high explosive of the true AC type tested depends naturally on its specific gravity, with the result that it ranged from 0.4 g for nitrocellulose, which is composed of gun cotton and collodion cotton, to 2.4 g for nitroglycerin in the case of high explosives of the true AC type tested herein. 

Compressed Gun-cotton for Torpedo Warheads and Mines. About 10 g. is removed from the centre of the printer or slab by scraping with a horn spatula. The scrapings are placed in a glass beaker of 1500 c.c. capacity, two-thirds full of distilled water, and stirred frequently for fifteen minutes. After settling, the water is poured off and replaced by the same qxtantity of water. It is again stirred for fifteen minutes, allowed to settle and decanted. The sample is collected by hand and the excess of water squeezed out. The wet gun-cotton is spread on six thicknesses of filter paper. Six other filter papers are laid on top and the sample is treated as described abow for nitrocellulose pulp. 

The preparation gun-cotton fuses is exactly the same as that of gun-cotton. They can be tested as described in the section on Nitrocellulose (p. 33). These fuses transmit fire faster than any other form, and are mostly used for firing laige set-pieces they burn very fast, and will fire a fuse-paper wrapped round them with absolute certainty they have the further advantage that they can be used in wet weather. 

In their standard recipe using pure nitromethane, they first put 17 parts by weight of nitromethane into a mixer, and then added one part by weight of nitrocellulose, and mixed the two until a gel was formed. Nitrocellulose is another name for gun cotton or smokeless powder, and it is easily purchased from reloading suppliers. Be sure not to get black powder for a muzzle loader. Read the label before buying ... 

Pyroxylin. Cellulose nitrate nitrocellulose collo -dion cotton soluble gun cotton collodion wool colloxylin xyloidin celloidin Parlodion. Variable mixture which con -sists chiefly of cellulose tetranitrate. Review R. T. Bogan el al. in Kirk-Othmer Encyclopedia of Chemical Technology vol, S (Wiley-Interscience, New York, 3rd ed.. 1979) pp 129-143. 

---