A classical experiment: nitrated cellulose wadding

[woelen]

This is a real classical experiment, but it is always fun to do it.

 

http://woelen.scheikunde.net/science/chem/exps/nitrocotton/index.html

 

This makes nitrated cellulose wadding, which IIRC also is called guncotton. It burns really fast with a brilliant orange flame. Have fun, but please be careful!

[Cesium]

This is indeed very fun to do. It's what magician's flash paper is made out of. I've nitrated cotton before with a mix of KNO3 and excess H2SO4. Good for those who don't have nitric acid.

[woelen]

Could you provide a little more detail on what to do with KNO3 instead of HNO3? That would be a nice addition to my webpage. Is it simply adding some KNO3 to H2SO4 and then adding the piece of wadding, or is it more involved? If you provide guidelines for that, then I could try them and add it to my webpage. It makes the experiment accessible to a larger group of people. Another variation may be the use of NaNO3, which is very common at the place where I live, as chili-salpeter.

[Cesium]

I followed the directions almost exactly from here: http://cavemanchemistry.com/cavebook/chfertilizer3.html

[woelen]

Looks somewhat messy, but I'll give it a try. What strikes me is the short nitration time. It only needs to be in the mix for 2 minutes instead of 20 minutes. I assume this is because there hardly is any water in the paste, while in my liquid with 65% HNO3 there still is some water.

[[w00t]]

i nevr could of made nitrocellulose (cellulose hexanitate) from cellulose and kno3(pure white)/90%+ h2so4

 

i tried to many many many times but my result was something that didnt even burn.

 

my resulting cutton looks nothing like that in those 2 websites

[YT2095]

Nice result!

 

I tend to find most of the times I`ve tried this, my cotton just ends up dissolving into a sludge within seconds, other times I get a product that looks similar to yours but burns like ordinary cotton.

 

I`ve had reasonable luck with unbleached Filter paper in the past though.

 

it might be a neat second step to dissolve it in acetone and then evap, leaving a pure product, or find a way to Spray it out and evap as it falls leaving an NC powder.

[[w00t]]

Nice result!

 

I tend to find most of the times I`ve tried this' date=' my cotton just ends up dissolving into a sludge within seconds, other times I get a product that looks similar to yours but burns like ordinary cotton.

 

I`ve had reasonable luck with unbleached Filter paper in the past though.

 

it might be a neat second step to dissolve it in acetone and then evap, leaving a pure product, or find a way to Spray it out and evap as it falls leaving an NC powder.[/quote']

 

 

ahh it turns to a sludge because sulfuric acid starts eating away cotton and changes the structure i think.

 

i get the samething, i also get a product that looks like what i started out with and burns the same way if not worst

[woelen]

I also did the result with paper tissue also, and that result in something which does not burn better than plain tissue without the nitration:

 

http://woelen.scheikunde.net/science/chem/exps/expshow.cgi?index=281

 

Apparently, the choice of wadding is important. I use pure snow-white cotton wadding, but I'm not sure how common that is in other countries. I have seen this stuff over here, in Germany and other countries nearby, but maybe in other parts of the world it is less common?

[Skye]

Cotton wadding is very common. You should be able to get it at a supermarket as cotton balls.

[jdurg]

You can also take your NC and mix it with a plasticizer and you'll get a material that is commonly used to make ping-pong balls. Trust me, ping-pong balls go up in a nice quick burst of flame if you light them on fire. Found out the hard way in college.

[YT2095]

IIRC, they use Camphor in ping-pong balls too.

if you dissolve some in acetone and leave it for a while, you can even smell it slightly.

[jdurg]

After learning that they were made with an NC based material, I had some fun with a not-so-bright buddy of mine. We had a black-out on campus due to a hurricane, and at night I told my buddy that ping-pong balls were filled with methane and made out of an explosive. He had a box of them for some reason but didn't believe me. I remember him going out in the hall and then hearing a big "WHOOSH" and a bright flash followed by some vulgarities and a rolling ball of fire going past the door to my room. The carpet had a nice singe-mark on it from the burning ball. hehe.