Nitrocellulose

Nitrocellulose (also known as cellulose nitrate, flash paper, flash cotton, guncotton, and flash string) is a highly flammable compound formed by nitrating cellulose through exposure to nitric acid or another powerful nitrating agent. When used as a propellant or low-order explosive, it was originally known as guncotton.

Henri Braconnot discovered in 1832 that nitric acid, when combined with starch or wood fibers, would produce a lightweight combustible explosive material, which he named xyloïdine. A few years later in 1838, another French chemist, Théophile-Jules Pelouze, treated paper and cardboard in the same way. Jean-Baptiste Dumas obtained a similar material, which he called nitramidine. These substances were highly unstable and were not practical explosives.

However, around 1846 Christian Friedrich Schönbein, a German-Swiss chemist, discovered a more practical solution. His preparation method was the first to be widely imitated—one part of fine cotton wool to be immersed in 15 parts of an equal blend of sulfuric and nitric acids. After two minutes, the cotton was removed and washed in cold water to set the esterification level and remove all acid residue. It was then slowly dried at a temperature below 40 °C (104 °F).

Nitrocellulose in The Guns of the South
Colonel George Rains was given the task of examining the powder in the ammunition of the new AK-47 repeating rifles by General Robert E. Lee in the hopes of duplicating it. Rains discovered the powder consisted of nitrocellulose and a nitrate of glycerin. The former Rains had known about from previous research by a German named Schönbein. Rains confirmed both by close examination of the fibers and chemically that the substance was nitrocellulose but the latter was a very unstable compound which exploded at the slightest touch. Rains was unable to duplicate the AK-47 ammunition but remained hopeful that with further study of other substances in the powder mixture he would be able to eventually duplicate it.