 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
Other Projects:
Nitrocellulose
Nitrocellulose
is the same chemical ping pong balls, fingernail polish, guitar picks,
and fine wood varnish is made of. It is also the primary chemical in
smokeless gunpowder. The raw cotton form is used for magic tricks and
small special effects. In fireworks, it is used as a binder in some
star compositions that may not be wet with water. Nitrocellulose is
also used as a coating on waterproof visco fuse.
Nitrocellulose is a nitrated form of cotton made by submersion in nitric acid. Sulfuric acid
is typically used to stabilize the reaction and the resulting
nitrocellulose. There are several processes to achieve the same end
result. The first is to simply form a solution of concentrated nitric
and sulfuric acid straight from the bottle to then use as a nitrating
bath. A second process, and the one I most often use, is to nitrate the
cotton with a solution of potassium or ammonium nitrate and sulfuric
acid. The nitrate forms nitric acid when introduced to sulfuric acid,
skipping the intermediary step of distilling pure nitric acid.
Safety Notes:
This process involves concentrated sulfuric and nitric acid in solution, and acid vapors in the air. It must be done outside on a windy day with nothing downwind, or in a fume hood. Nitrocellulose may only be made in the quantity described or smaller, never larger. If a larger quantity is attempted, or if the ice salt bath is not used, a runaway reaction is likely to occur that evolves a lot of very toxic red gas. It should be avoided at all cost. If a runaway starts to occur (as evidenced by red gas), avoid the gas, and quickly drop the reaction beaker into a water bucket standing by. This will dilute the reactants and stop the reaction.
Even when a runaway reaction is not occurring, the solution will constantly give off colorless acid vapor which should also be avoided.
Safety glasses and chemical resistant gloves must be worn at all times to protect from acid splash that occurs from stirring. Should any acid come into contact with your skin or clothes, the water bucket that should be standing by in case of a runaway may be used to quickly wash.
Synthesis:
Safety Notes:
This process involves concentrated sulfuric and nitric acid in solution, and acid vapors in the air. It must be done outside on a windy day with nothing downwind, or in a fume hood. Nitrocellulose may only be made in the quantity described or smaller, never larger. If a larger quantity is attempted, or if the ice salt bath is not used, a runaway reaction is likely to occur that evolves a lot of very toxic red gas. It should be avoided at all cost. If a runaway starts to occur (as evidenced by red gas), avoid the gas, and quickly drop the reaction beaker into a water bucket standing by. This will dilute the reactants and stop the reaction.
Even when a runaway reaction is not occurring, the solution will constantly give off colorless acid vapor which should also be avoided.
Safety glasses and chemical resistant gloves must be worn at all times to protect from acid splash that occurs from stirring. Should any acid come into contact with your skin or clothes, the water bucket that should be standing by in case of a runaway may be used to quickly wash.
Synthesis:
(Gun Cotton, Flash Cotton)
40 mL
sulfuric acid (~95% conc.) is measured into a beaker, and 25 grams of potassium
nitrate dissolved into it. The nitrate will be difficult to dissolve,
but it can be done with much stirring. At this point the solution will
begin to evolve clear acid vapor which should be avoided.
The beaker is then placed into an ice salt bath and let cool down to temperature. The salt will allow the water to cool to a lower temperature than were it filled with ice alone.
4 cotton balls (~2.5g) are then added to the beaker, and worked into the solution with a stir rod or spoon. This will be difficult because the solution will have turned syrupy from the cold. When the cotton balls are well worked in, the reaction is left to sit for a half hour. When that time is up, the beaker is removed from the ice salt bath and left at air temperature.
Another 10-15 mL sulfuric acid is added and the cotton balls are well worked over again with the stir rod. Any hard knots felt in the cotton must be worked with the rod to allow access to the solution. The beaker is then left to sit for an hour or more.
At this point the cotton balls are removed and placed in water. They must be washed several times with water to remove much of the acid within them. When washed as well as possible, they are then placed into a sodium bicarbonate (baking soda) solution and worked with the hands until no more bubbles form. They may have to be washed with bicarb several times to fully neutralize. Several more washes with water to remove excess bicarb and the nitrocellulose is complete.
The nitrocellulose will now be very tangled and knotted. For best performance, it must be pulled apart and made fluffy as cotton once again. This is a very tedious job to do by hand. The nitrocellulose must be fully dry for use.
This process can be done to cotton in any form. Thin fabric or paper may be used to make flash paper, though it is difficult not to rip it during nitration. A glass tray may take the place of a beaker to nitrate sheets of cotton more effectively.
The beaker is then placed into an ice salt bath and let cool down to temperature. The salt will allow the water to cool to a lower temperature than were it filled with ice alone.
4 cotton balls (~2.5g) are then added to the beaker, and worked into the solution with a stir rod or spoon. This will be difficult because the solution will have turned syrupy from the cold. When the cotton balls are well worked in, the reaction is left to sit for a half hour. When that time is up, the beaker is removed from the ice salt bath and left at air temperature.
Another 10-15 mL sulfuric acid is added and the cotton balls are well worked over again with the stir rod. Any hard knots felt in the cotton must be worked with the rod to allow access to the solution. The beaker is then left to sit for an hour or more.
At this point the cotton balls are removed and placed in water. They must be washed several times with water to remove much of the acid within them. When washed as well as possible, they are then placed into a sodium bicarbonate (baking soda) solution and worked with the hands until no more bubbles form. They may have to be washed with bicarb several times to fully neutralize. Several more washes with water to remove excess bicarb and the nitrocellulose is complete.
The nitrocellulose will now be very tangled and knotted. For best performance, it must be pulled apart and made fluffy as cotton once again. This is a very tedious job to do by hand. The nitrocellulose must be fully dry for use.
This process can be done to cotton in any form. Thin fabric or paper may be used to make flash paper, though it is difficult not to rip it during nitration. A glass tray may take the place of a beaker to nitrate sheets of cotton more effectively.
Items used for initial synthesis:
40 mL sulfuric acid:
Potassium nitrate and sulfuric acid nitrating solution:
Beaker in ice salt bath, cotton freshly added:
Beaker removed from bath after first half hour. 10 mL sulfuric acid added:
Washing and neutralizing:
Finished product:
