Ping pong balls cut up and ready to dissolve.
Acetone added and celluloid starting to dissolve.
Finished pyroxylin at the right viscosity.
Ping pong balls are commonly made of a material called celluloid. Celluloid is a mixture of nitrocellulose and camphor. They are mixed together and heated to produce a plastic like material. Some cheaper balls are made with other plastics and won't work for this. The camphor can be smelled when the balls are cut open and is a good sign they are made of celluloid.
Pyroxylin is a mixture of nitrocellulose dissovled in a solvent. nitrocellulose is cellulose that has been nitrated with nitric and sulfuric acid. There are three levels of nitration, mononitrocellulose, dinitrocellulose, and trinitrocellulose. pyroxylin is made from the mono and dinitrocellulose and is flammable but not explosive like trinitrocellulose.
I made the pyroxylin by cutting up the ping pong balls into small pieces to speedup the process and then in a glass container added acetone in excess as the solvent. I let the pieces dissolve,the camphor which is a wax like material was dissolved in the acetone as well. I remove the excess acetone to remove as much of the camphor as possible. A white gel like material is left over and to this I added more acetone and stirred until it was the viscosity I wanted. I will be using the pyroxlin solution in the future for pyrotechnic projects.