Nitrocellulose

Nitrocellulose is a highly flamable compound formed by exposing cellulose to nitric acid. It was used during World War I and World War II in smokeless gunpowder. Other uses include plastics, films and membranes for Western blot.

Depending on the manufacturing process, the nitrocellulose is esterified to a varying degree. Table tennis balls and some photographic films, for example, have a fairly low esterification level and burn rather slowly with some charred residue. The first cine films were made using nitrocellulose; decades later, it was discovered that nitrocellulose gradually decomposed, releasing nitric acid, which further catalysed the decomposition. Salvageing old films which were undergoing this accelerating self-catalysed disintegration became a major problem for film archivists.

Nitrocellulose can be made by putting cotton wool (almost pure cellulose) into a mixture of 2 parts sulfuric acid and 1 part nitric acid. The time in the bath will determine the esterification level. Afterwards the cotton wool needs to be washed and dried thoroughly. This should not be tried at home, as it involves harmful substances.