Quote: Originally posted by Hey Buddy  | I've been doing sabanejeff-oxidation derived lead azide (dextrin and cmc). I saw this demonstration set up on Astral Chemistry's video channel. This
photo is the first arrangement used. I copied his set up. Sidearm test tube as reaction vessel. HN3 diluted with N2 and NO2 is generated and fed into
a broke off pipette tip through a two hole stopper into lead acetate/cmc/dextrin aqueous solution. The other hole in the stopper has a short section
of pipette connected to a vinyl output hose feeding into a water trap. Hydrazine sulfate and 50% concentration nitric acid are loaded into the
reaction chamber, a gentle heat is applied to the reaction tube, around 30 sec to a min of heating by an electric heat gun initiates the reaction
smoothly. Generating a movement of the reaction mixture and a fizzing followed by bubbling then intense bubbling then tapering off. Mixed HN3 gas is
fed into the receiver chamber loaded with your solution of choice, inorganic hydroxides, acetates and nitrates are the usual solutions.
I have not attempted this with organic substrates. I have been trying this set up using OTC drain cleaner/ AN in situ nitric acid salt mix, instead of
the usual diluted HNO3. It generates HN3 almost as smoothly as using HNO3.
I have had some lessons learned using this set up. Obviously, HN3 is the greatest danger presented by any method using hydrazoic acid, its very
poisonous and explosive when concentrated. This method is advantageous in that its risk of detonation is minimized by small amounts of gas produced at
a time as the reaction proceeds and the gas then neutralized at end point use creating azide directly. The gas is also diluted by the nitric acid
presence which is definitely feeding NO and NO2 and maybe some N2 into the stream.
The gas pressure can become intense depending on the vessel and mass of reactants. Astral recommended 1.5 g N2H6SO4 for 4 cc of 50% HNO3. That ratio
works smoothly. In modifying the procedure to use NO3 salt, I tried at first mixing hydrazine salt with nitrate salt in the reactor and adding H2SO4.
This results in quite an immediate reaction. Ive also blown off the stopper from excess gas pressure from too vigorous of a gas generation, this
should be avoided because it off vents hydrazoic acid into the ambient environmentif you are not using a hood. A better method is to first react the
H2SO4 with nitrate salt for around 15 minutes prior to loading it into the reactor with the hydrazine inside. This method has no immediate reaction
and a reaction doesnt begin until the reactor is heated to around ~100 C.
I have also had issues with bubbling of reaction mixture through the side arm into the receiver. This makes a mess. The solutions I found helpful were
using a larger 125 ml flask as the reaction vessel with a longer section of hose fed into the receiver. The hose is connected to a section of 90
degree glass pipe through a one hole stopper. The stopper to the flask is much larger than the test tube stopper and squeezes in tightly with a
greater surface area. It has not fired off into the air like the original set up. As of now reaction batch sizes are increased to around 5 ml H2SO4/AN
with 5 ml H2O and 3 g hydrazine sulfate.
Hoses degrade from the gasses and so they are consumables in this method but very short lengths are used. I should also mention that I leave the area
after the reaction begins and allow it to proceed for 30 min before returning. If I have to stay in the area next to the reactor, I put a stack of
bricks in front of the glass for the unlikely hazard of detonation. For clean up I use paper towels and a waste beaker and put all of the contents
into a hot fire out doors after cleaning. Im still working on optimizing this method but I thought it was pretty basic and simple. The process that is
occurring isnt well understood but its believed to maybe be a breakdown of N2H4 HNO3 into HNO2 that then forms HN3. Using a mixed nitrate salt drain
opener reaction mix along with simple hydrazine sulfate makes this method of azide very simple compared to other methods. Azide can be prepared
quickly because the reaction is only around 15 minutes and the preparation is very minimum as there is no staging. No requirement of nitrite and
hydrazine sulfate can be used direct without free basing.
edit:
I would like to know how other people clean up their equipment after making azides. I would imagine that there are some tips I could pick up because
other than making a nitrite bath and dumping everything in, I'm not sure what the best way to clean up is other than rinsing everything with water and
using paper towels then incinerating everything,.
[Edited on 7-1-2023 by Hey Buddy]
[Edited on 7-1-2023 by Hey Buddy] |
Interesting read. I had the luxury of Sodium azide being available back when I was younger and braver- Glad you've survived learning this process
(so far). Also glad you have had the foresight to barricade the process and retire, this is well into the "WHEN, not IF something will go wrong"
category.
I'm not going to replicate these processes, I'm not brave enough to play with free HN3. You've no doubt read the toxicology information and the
copious historical material on HN3 related accidents? Incidents like a university maintenance worker getting some fingers blown off when disassembling
chemistey lab hood duct work which HN3 had been vented through, various deposits of contaminants in the duct & the rivets fastening the ductwork
together having become coated with primary explosives thereby?
Years ago, I used a bit of amorphous silver azide in some small special effects charges to emulate bullets striking metal surfaces for a video.
Shooting outdoors on a windy, dry, cold fall day, our crew was wearing some wool and synthetic clothing (static electricity generating). One of the
scenes needing to be re shot, my partner reached into the .50 BMG mmo box where a number of these small charges were stored, individually taped to
cards and (we thought) well enough separated to prevent mass explosion. On touching one of these cards, static fired the device and several others in
the container- I re read the literature on ESD sensitivity of primary explosives and quit making/using silver azide.
Be careful and don't get acclimated and blase about personal protection, always proceed on the assumption that such things will explode during
processing/storage- Because if you work with them often enough, eventually, they will. |
