What is nitrocellulose cotton?

Nitrocellulose is an organic compound that is highly flammable. It was originally made by soaking cotton in nitric acid. It can be used as a low order explosive or propellant (for example, gunpowder) and is called "gun cotton" for that reason.

Once it became possible to adjust the produce with moderators, it was the basis for the smokeless gunpowder introduced by the French military with the Lebel rifle in 1886, the first firearm to have smokeless gunpowder. The advantages included lack of smoke to obscure the battlefield, and a large reduction in fouling in the rifle, meaning that the rifle could fire many more times before it was necessary to clean it. The pressures generated were higher than what the older gunpowder produced, so it was necessary to use it cautiously in older weapons.

Nitrocellulose was also an early plastic, and useful as such. The original photographic film introduced in 1889 by Kodak was made of nitrocellulose, and it was used for movie films as late as about 1951. Since it decomposes spontaneously, this use is part of the reason many old films no longer exist. It was an occupational hazard for movie projectionists that the film could catch fire in a hot projector, and since there was a lot of highly flammable film in a small projection room, this could easily prove lethal. Old movies may not be mailed or sent by most common carriers for that reason. In fact, it is probably best that old movie film be safely destroyed. Local hazardous waste disposal people might be consulted on this.

Nitrocellulose was put to other uses. It was the basis for early celluloid. In the early days, it was still explosive due to imperfections, and billiard balls coated with celluloid exploded often enough that billiard parlor owners complained.

Nitrocellulose based celluloid, moderated with fine clay, provided the white facing on some slide rules, right up to the end of the slide rule era.