Sciencemadness Discussion Board

Help Making Nitrocellulose

MYooFC - 6-5-2016 at 06:55

I am making gun cotton, nitrocellulose, for a class demonstration and I was wondering the best way to make it. Although the basic procedure that I have seen is the same, there are differences. So my questions are:

1. What is the best concentration(s) and proportion(s) of sulfuric and nitric acid to use?

2. What is the best cellulose to use (cotton balls, toilet paper, etc)?

3. Is it necessary / that important to use an ice bath?

Metacelsus - 6-5-2016 at 07:11

1: Read this:
2: Cotton balls are probably best, but make sure they're actually cotton, and don't contain polyester.
3: Yes. Runaway reactions are not pleasant to experience.

a nitrogen rich explosive - 6-5-2016 at 07:23

Nitrating string can be quite fun. Anyway, don't use anything with synthetic fibres: I tried to nitrate a pair of underwear with rubber elastic and got a bunch of nasty fumes.

solitanze - 6-5-2016 at 08:21

For best results, boil cotton balls in a 2% solution of NaOH for an hour or so, then wash thoroughly to remove all base and dry.

XeonTheMGPony - 6-5-2016 at 08:29

Quote: Originally posted by solitanze  
For best results, boil cotton balls in a 2% solution of NaOH for an hour or so, then wash thoroughly to remove all base and dry.

Thank you, I will try this next time I make some.

a nitrogen rich explosive - 6-5-2016 at 16:09

Shouldn't this be in EMs?

Herr Haber - 6-5-2016 at 17:23

If you dont use an ice bath you might end up with a runaway.
I you dont want to use an ice bath make sure you chill your nitrating mixture and the room temperature doesnt exceed 25 c°.

Cotton balls are the best. NaOH as suggested is a good way to get rid of many things (grease for ex) that WILL lead to a runaway.
I tried nitrating cotton string but the results were disappointing: since the string is woven the acids dont get Inside well enough. It will burn, but you will have a lot of residue.

Also, once you have your NC make sure to stabilize it as best as you can. NaOH at this point is counterproductive but baking soda is fine.
I sometimes boiled mine or used a tray that goes above a cooking pot to cook vegetables.

Since you want to use this for a class demonstration here are a few tricks I learned.
- Keep your container away from where you'll be burning your NC. Far as in "not in the other hand"
- If you plan to burn some in your hands of other people hands make sure their hair / face is not in the way !
- Make it as fluffy as possible if you plan to burn it in your hands. Separate the fibers as much as you can. Otherwise, if it's too dense you'll burn yourself. Not badly, but it ruins the charm :)

Volanschemia - 6-5-2016 at 22:55

Also, make sure that whatever you are nitrating is completely submerged in the nitrating mixture. I have found that if any of it is exposed to air (ie. protruding above the liquid level), it gives off a lot of NO2.