Sciencemadness Discussion Board

ETN ignition problems?

Hockeydemon - 7-7-2013 at 23:17

I made some ETN the other day, just 3g of it. I don't have my lab notebook with me, but I believe I used 12mL HNO3 & 18mL H2SO4 with 3g of erythritol. I kept everything below 20C, and allowed the mixture to stir on a stir plate for ~30mins. Then I filtered, and dried the crystals.

My issue is with when I actually ignite the ETN. If I place a small amount on tin foil, and hold a blow torch to it nothing really happens. It will just liquefy & burn up. So I figured I'd try to ignite it through impact. I wrapped another small quantity up in tinfoil, and subjected it to force impact. Nothing happened.

I then tried the blow torch on the ETN I just subjected to impact, and POP! I repeated this a few times tinkering with what I did, and it will only light after it's been struck with a hammer.

The only thing I can think of is the ETN crystals after impact are in better contact with the Aluminum foil?

Any insight?

NeonPulse - 8-7-2013 at 01:12

not much really does happen- it should just burn with a small burst of flame. the etn i have made previously does not always detonate with the hammer test either. it's sensitivity also depends on which solvent you used to re-crystalize it with. i hear methanol and acetone make for the most sensitive product, i have only used ethanol with about 1/6 of acetone to help it totally dissolve and i get the desired crystal size and density for my purposes. i would like to try methanol though.

Chill - 8-7-2013 at 12:30

Quote: Originally posted by NeonPulse  
not much really does happen- it should just burn with a small burst of flame. the etn i have made previously does not always detonate with the hammer test either. it's sensitivity also depends on which solvent you used to re-crystalize it with. i hear methanol and acetone make for the most sensitive product, i have only used ethanol with about 1/6 of acetone to help it totally dissolve and i get the desired crystal size and density for my purposes. i would like to try methanol though.


Heet antifreeze is a quick source of methanol. You can get 12oz for about a buck.

Bot0nist - 8-7-2013 at 12:33

I always use 95% ethanol for a great recrystallization. Try enclosing a small piece (very small) tightly in the end of a little foil "wand" and then hold it into a flame. It will make your ears ring. I assure you. Make sure the piece is smaller than a match head, and make the "wand" long enough that it is a good distance from your hands and face. And wear goggles, cause foil will fly.

Have fun.

EDIT: also, for impact testing, place the pace in a tight foil ball, and then put it on a smooth, steel surface, like an anvil, then hit it with a flat steel hammer. The surface texture and density of your impact testing apparatus is very important. Concrete and stones rarely work. Not wood and linoleum either. Steel on steel.

[Edited on 8-7-2013 by Bot0nist]

Hockeydemon - 8-7-2013 at 14:54

What are the various advantages to different solvents when recrystallizing? I have methanol, and ethanol, but I used sodium bicarbonate to neutralize it. Is it a matter of shelf life or overall quality of the final product?

I think I might have failed to articulate my question though.

If I take a small amount, and hold a flame to it regardless of if it's exposed to the air, or tightly wrapped in foil nothing happens. Same goes for if I impact it (though I have been using a hammer on smooth concrete - not steel).

The question is why would it only go off after I've impacted it? So I wrap it in foil, smack it with a hammer, and then hold a flame to it and it will go off. Why is impacting it making it susceptible to a flame ignition?

golfpro - 8-7-2013 at 15:15

press it hard when it's in the aluminum foil, it should be easy.. I am more intrigued by how you made Nitric Acid.