nitrocellulose, nitric acid ester of cellulose (a glucose polymer). It is usually formed by the action of a mixture of nitric and sulfuric acids on purified cotton or wood pulp. The extent of nitration and degradation (breaking down) of the cellulose is carefully controlled in order to obtain the desired product. When cotton is treated so that nearly all of the hydroxyl groups of the cellulose molecule are esterified, but with little or no degradation of the molecular structure, the nitrocellulose formed is called guncotton. Guncotton resembles cotton in its appearance. Extremely flammable, it explodes when detonated and is used in the manufacture of explosives. Guncotton is insoluble in such common solvents as water, chloroform, ether, and ethanol. If the nitration is not carried to completion (the point at which about two thirds of the hydroxyl groups are esterified), the soluble cellulose nitrate pyroxylin is formed.