Unforseen Happening With nitration of cellulose

[DONMAN]

I was just finishing my nitration of cellulose, and I was squeezing the acid out of the nitrocellulose with my thick rubber gloves, when all of the sudden I feel this heat from the glove and it partially combusted burning the glove. I was using the NH4NO3 method of nitration, if that helps....

Now I have a few theories as to what caused this:

I squeezed the acid out so much that I partially dried out the cotton causing it to be very sensitive, as it hadn't been neutralized with a base yet.

or.

The glove reacted with the acid forming some organic nitrate that under the heat of its own nitration ignited itself.

Just wondering if any of you had any input on what happened chemically?

[nbk2000]

I'd say acid reacting with the glove rubber.

What kind of 'rubber' are these gloves? Latex, nitrile, butyl, neoprene?

[DONMAN]

They where latex. What should I use in place of them?

[nbk2000]

Something other than your hands, perhaps? ;)

Press it in between 2 blocks of wood.

[FUTI]

God that was stupid choice of gloves...oh well we all learn sometimes by mistakes. IIRC ACS president several years ago make a (false) press statement about condoms aren't safe because size of the pores on the latex they are made of (like on gloves) is larger than the size of the AIDS virus causing the turmoil among the sheepish population. While that was true for the gloves which was made (at that time - I'm not sure how do they make them today) by one-layer process, it was false for condoms which are always made by two-layer process. While this seem like OT...point of the tale is...you choose the thinest and least protective thing to do the job.

Hell I have seen some nasty mustard like substance/solution easily pass through neoprene/nitrile gloves so you can't be 100% safe ever but I hate latex as to prone to leakage, solvent penetration and mechanical instability upon the contact with some solutions.

[nbk2000]

Latex is solidified tree sap, so how good can that be against fuming acids?

[DONMAN]

Well these where 4 ply so I thought that they could handle the job. They weren't like medical exam gloves, although they where latex :( ....

I am defiantly going to go pick up some more industrial gloves!

Live and let learn. It wasn't smart in the first place to wring it out by hand, I just didn't want to have to waist so much base in neutralizing all that acid. I am a cheapskate :)

[Bert]

Go to your hardware store and tell them you're acid washing concrete. Get the rubber gloves masons use for that job- Not good for jewelry work, but very strong & acid proof. It is not uncommon for guncotton to ignite in the acid removal centrifuges in industrial plants- Just the moisture in the air on a humid day can raise the temperature of the acid damped fiber enough to cause ignition.

[SafetyLast]

Use nitrile gloves, nitrile is synthetic latex. They contain no latex proteins and are resistance to punctures and tears. They are resistant to many types of chemicals. PVC gloves also work good, I used to have a really good pair of high cuff pvc acid gloves.

I personally use tongs for squeezing my wet nc.

I've never had good success from the AN nitrating method the dry product burned slowly, taking about 3-4 seconds for a thumbnail sized wad to burn! It left a lot of black ash as well leading me to believe that it was only slightly nitrated like the celluloid that ping-pong balls are made from.