Sciencemadness Discussion Board

Lead azide synthesis

Ral123 - 21-4-2013 at 09:38

Here's how I see a generic azide synth. A lot of people ask me and I decided to make a video:
http://www.youtube.com/watch?v=xRGJdbenK1c

chemcam - 21-4-2013 at 21:08

Wow, that seems very straight forward and simple. I have yet to experiment with any azides, I am hesitant to do a hydrazine synthesis without a stronger fume hood.

I would like to compliment you on your overhead stirring apparatus, It would seem to me that we both are very mechanically inclined people. That talent seems to be declining, most homemade things I have seen lately look like something from a horror film that will fail just by looking at it. I wish people would take the time to properly design and build what they need rather than buying from a large corporation. Everyone will be coming to us when some disaster happens and no stores are available.

Ral123 - 21-4-2013 at 21:43

Wow, thanks. Addition of the solution drop by drop takes quite a while. Manual stir will make your hand hurt and you can hit the wall or bottom of the vessel. For micro experimentation lead azide is great. For big AN based charges all azide can offer is marginal safety.

chemcam - 21-4-2013 at 22:19

Yeah all my energetic experiments are small scale so this would be ideal. I just need to further educate myself with hydrazine.

The overhead stirring device I made looks similar to yours but it mounts on my metal ring stand pole. I took a 12" 5mm glass tube and made it into an upside down T, sealed the ends and attached the other end to the motor shaft. I wired it to a variable resistor so I can control the speed.

Ral123 - 21-4-2013 at 23:22

These polypropylene pudding cups can withstand nitrating mixture. I've made MN and NG in these. It feels quite safe.

Finnnicus - 22-4-2013 at 00:57

Love the video. You are incredibly shakey though! Use a longer splint for comfort purposes :P

Ral123 - 22-4-2013 at 01:10

Imagine if I had to do the synth. in glass and stir manually :D

Fantasma4500 - 22-4-2013 at 11:31

Quote: Originally posted by Ral123  
Manual stir will make your hand hurt and you can hit the wall or bottom of the vessel.


can lead azide go off by just striking a tiny wet particle in between plastic??
also to solve this for ppl without such fancy gear a erlenmeyer flask might come in handy, filling it less than half for easier swirling ^^
swirling a erlenmeyer flask is the feeling of science. (=

Ral123 - 22-4-2013 at 12:24

Not that it's likely, but if a small plastic cup with azide synth. explodes and you are with safety glasses you wont be hurt at all. It wont even be loud. The glass however can be nasty. AP feels kinda stable when is drowned in water. Azide is known to be quite potent and sensitive, even when wet.

Bot0nist - 22-4-2013 at 13:14

Your right about using the thin plastic reaction vessels when you can. I used small, HDPE test tubes when I made M.E.K.P. and other sensitive primaries, when it was possible.

Yes, the plastic can still fragment and produce shrapnel, but it is of much less density, so it travles slower and less distance. A rigged up blast shield or fumehood curtian is a great idea. Or a face shield. At the very leas, goggles.
You took into account the extreme toxicity of the sodium azide as well, I assume.
Nice video. Thanks Ral.

edit: spelling.
I am sorry to everyone for the spelling as of late from me. My only connected device at the moment is a crappy "blackberry, style cheap phone. The buttons are tiny, my thumbs large and insensitive and weathered from manual labor. The browser also lack a spellchecker or auto correct feature, and the built in predictive text feature is so difficult to work that it ends up making things worse, when coupled with the prevously mentioned thumb hinderance. And, I am just a terrible speller, and have been known to abuse commas, also. I will try and upgrade soon.
;)


[Edited on 22-4-2013 by Bot0nist]

Motherload - 15-2-2014 at 19:22

Sorry to bring up an old thread but ..... This the most relevant place to ask.
I recently acquired 500 gms of NaN3 :D but the shitty part is I had spent sooo much time making Hydrazine Sulfate and after making about 200 gms of it I had the opportunity to buy the NaN3 but regardless I want to make some Pb(N3)2 now.

Would it be dangerous to mix dilute solutions of Azide and Nitrate and dextrin in a polypropylene beaker with a Teflon coated stir bar ?
Would there be a possibility of detonation from friction ?
I do notice the the stir bar typically pushes the sediment outward and away from its centre.

Ral123 I see you use a overhead mixer.

Ral123 - 15-2-2014 at 23:12

According to the literature the stir bar is very inadvisable as water doesn't desensitize LA that much.
My NaN3 was more then 50 years old, I guess if pure, yours can wait too.

Trinitrophenol - 3-5-2014 at 13:01

Hey anyone know about azides (sodium/lead azide) compatibility with stainless steel?

Dany - 4-5-2014 at 01:15

Lead azide is compatible with stainless stell.

here's a quote from [1]:

"...It is therefore necessary to prevent lead azide coming into contact with copper in its applications. Aluminum, stainless steel, tin, and lead do not react with lead azide even in presence of water. The preferred material for applications containing LA is therefore aluminum."

Reference:

[1] Robert Matyas & Jiri Pachman, Primary Explosives (Springer 2013)

Dany.

Ral123 - 4-5-2014 at 02:02

Does copper case offer any advantage over brittle aluminium or thin stainless steel? Only that it looks old school.

Dany - 4-5-2014 at 02:04

Ral123, what do you mean by this question? what advantage?

Dany.

Ral123 - 4-5-2014 at 02:15

The brittle aluminum will provide a little faster shock wave and allow the hot gases to contact the main material, unlike the copper witch may balloon.
Also if we try to set off anfo: Imagine these 1000m/s+ fast hot pulverised aluminum particles in the centre of your charge.
The only advantage of copper I can see is it's less reactive toward some things and it can be shaped and soldered.

Dany - 4-5-2014 at 02:20

Quote: Originally posted by Ral123  
The brittle aluminum will provide a little faster shock wave and allow the hot gases to contact the main material, unlike the copper witch may balloon.
Also if we try to set off anfo: Imagine these 1000m/s+ fast hot pulverised aluminum particles in the centre of your charge.
The only advantage of copper I can see is it's less reactive toward some things and it can be shaped and soldered.


What is the connection between the incompressible story that you are telling me and the subject of the thread???

Dany.

PHILOU Zrealone - 5-5-2014 at 07:01

Quote: Originally posted by Dany  
Quote: Originally posted by Ral123  

Does copper case offer any advantage over brittle aluminium or thin stainless steel? Only that it looks old school.

The brittle aluminum will provide a little faster shock wave and allow the hot gases to contact the main material, unlike the copper witch may balloon.
Also if we try to set off anfo: Imagine these 1000m/s+ fast hot pulverised aluminum particles in the centre of your charge.
The only advantage of copper I can see is it's less reactive toward some things and it can be shaped and soldered.

What is the connection between the incompressible story that you are telling me and the subject of the thread???

Dany.

He apparently tries to give his 50 cents on your data.
But he misses the point that copper is not compatible with lead azide.

Copper can be "cooked" and becomes then harder than aluminium at equivalent thickness (it becomes also much more brittle). Stainless steel is even harder. Usually when one tends to push the VOD/density of the primary, he needs the stronger material. So stainless steel > hard copper > soft copper > lead; and iron > glass > hard plastic > paper > rubber.

Here I think that in your reference they go for aluminium over stainless steel because of price reasons.

@Ral123,
The statement that Copper will "inflate like a balloon" is not possible at the speed, overpressure and heat of the detonic process inside the cap...it will be fragmented or reduced to copper dust.

Trinitrophenol - 5-5-2014 at 10:21

Thanks a lot for you answer Dany! Very much appreciated :)
But when you make lead (II) azide do you need commercial/pyro grade dextrin or would just home baked corn starch do the job?
After my experience homemade dextrin won´t dissolve that easily in water and might not dissolve completely.

Motherload - 5-5-2014 at 11:12

Also, I have seen glucose refered to as dextrin. Normally as dextrose.
So the " impurity " we add in to prevent the crystals from getting to big ..... Is it regular corn starch ? I can't seem to find any starches labeled dextrin.

I am going to buy one of those cheapo personal coffee/drink whisks and turn down the rpm and use to stir.

Ral123 - 5-5-2014 at 14:15

In my experiments adding very little sugar reduces the size of the crystals. It also makes the product much less flame sensitive. I don't know if it's because it attracts water.
@PHILOU Zrealone
Why would case hardness matter so much for the velocity. My foil(bad idea) and straw detonators work fine. May be case hardness contributes to DDT and case weight and density to velocity.

Bert - 5-5-2014 at 18:55

Quote: Originally posted by Motherload  
Also, I have seen glucose refered to as dextrin. Normally as dextrose.
So the " impurity " we add in to prevent the crystals from getting to big ..... Is it regular corn starch ? I can't seem to find any starches labeled dextrin.


Dextrin can be made FROM corn starch, by roasting it carefully with frequent stirring in your kitchen oven.

Or you could toast some bread, scrape off the brown surface, and dissolve the dextrin in water. Filter the water and dry the filtrate to recover dextrin.

Wichita buggy whip-Dextrin procedure

PHILOU Zrealone - 6-5-2014 at 05:43

Quote: Originally posted by Ral123  
In my experiments adding very little sugar reduces the size of the crystals. It also makes the product much less flame sensitive. I don't know if it's because it attracts water.
@PHILOU Zrealone
Why would case hardness matter so much for the velocity. My foil(bad idea) and straw detonators work fine. May be case hardness contributes to DDT and case weight and density to velocity.

Suggar catch indeed more water from the air than dextrin would; in moist weather your Lead di-azide will be harder to ignite.

Hardness matters apparently.

For a given explosive material, at an equivalent density and internal diameter; tubes of different materials do detonate at different VOD. So the casing is important.

With a harder casing, you can press harder (for primaries that allow this) and increase the weight of primary per volume (thus the density).
Hardness (non deformability) of the casing increases the shockwave confinement, but explanation is probably also partly due to the speed of sound propagation into the casing material (?)... there seems to be a correlation between this and the VOD as a function of the casing material.
Speed of sound into materials

Dany - 6-5-2014 at 14:04

Quote: Originally posted by PHILOU Zrealone  
Hardness matters apparently.

For a given explosive material, at an equivalent density and internal diameter; tubes of different materials do detonate at different VOD. So the casing is important.

With a harder casing, you can press harder (for primaries that allow this) and increase the weight of primary per volume (thus the density).
Hardness (non deformability) of the casing increases the shockwave confinement, but explanation is probably also partly due to the speed of sound propagation into the casing material (?)... there seems to be a correlation between this and the VOD as a function of the casing material.
Speed of sound into materials


A heavily confined explosives is equivalent to a large diameter charge and as detonation velocity depend on charge diameter a harder confinement will help the achievement of maximum detonation velocity at the density of the explosive under test. The sound speed of the casing has no effect unless in some cases like a liquid explosive detonated with a weak iniator or a liquid explosive which detonate near its critical diameter. The sound speed of the casing play a role in what is called low velocity detonation for more on this read this old comment and reference therein. For more on detonation initiation and parameter affecting this initiation read this report.

Dany.

[Edited on 6-5-2014 by Dany]

NeonPulse - 24-6-2014 at 22:50

I was just curious to know a little more on the sensitivity of lead azide and have a couple of questions about it.
I have synthesized this compound a few times now and each time has produced great results and it is a brilliant primary explosive.
the synthesis i used was as follows:
2.33g sodium azide dissolved in to 70ml dist water, and 6.9g lead nitrate+ 0.35g dextrin in 90ml dist water in another plastic beaker.
3 or 4 drops of a 10% sodium hydroxide solution added to the lead nitrate sol to raise the PH to 5.
I then heated the nitrate sol on a hot water bath to 63c and stir while dropwise adding the azide solution to the nitrate/dextrin solution. immediate precipitation of the desired product was apparent.
taking around 10-15mins to complete the addition, the mix was removed form the water bath and allowed to cool to room temp with continued stirring. it was then filtered, washed and dried. Yeild was 5g probably a tiny bit more as some small losses from the filtering and crystals deposited on the walls of the beaker, which i was NOT going to attempt to scrape off...

The only differences with this latest synthesis was the stirring. I made an electric overhead stirrer similar to what Ral123 made. Its very efficient. the last times were stirred by hand. Could this stirring have made a product even less flame sensitive than hand stirring?
The reason i ask is this particular batch doesn't seem to want to detonate in small piles lit with a flame splint. It only ignites very quickly like mercury fulminate with a small pop and flash even with piles around 100mg (not weighed- just guessing). With a previous synthesis it was able to DDT in small amounts detonating violently. this latest batch will detonate but only with confinement, a solid whack with a hammer or a small amount heated in foil. I knew lead azide to not be particularly flame sensitive but not to the point it wont detonate in a small pile. is this normal behaviour for lead azide?



Hmmm, I see. Simple mistake. I did mean increase, and not really paying attention to detail. if I took the time to proof read my post before posting I wouldn't have made that mistake.oops.

[Edited on 25-6-2014 by NeonPulse]

Metacelsus - 25-6-2014 at 06:27

Quote: Originally posted by NeonPulse  

3 or 4 drops of a 10% sodium hydroxide solution added to the lead nitrate sol to reduce the PH to 5.


Adding bases increases pH.

Motherload - 15-7-2014 at 19:45

People have used sugar to reduce crystal size in LA synths .... Can glucose be used ... Is it critical ?
Glucose isn't as deliquescent and I have lots.

Energetic Einstein - 14-8-2014 at 08:41

Quote: Originally posted by Motherload  
People have used sugar to reduce crystal size in LA synths.


Is it necessary to do this, or can I just handle the LA after with a normal crystal size?

Loptr - 14-8-2014 at 08:54

Quote: Originally posted by Energetic Einstein  
Quote: Originally posted by Motherload  
People have used sugar to reduce crystal size in LA synths.


Is it necessary to do this, or can I just handle the LA after with a normal crystal size?


Is this related to the use of dextrin in LA (dextrinated lead azide)?

Energetic Einstein - 14-8-2014 at 13:54

Quote: Originally posted by Loptr  
Is this related to the use of dextrin in LA (dextrinated lead azide)?


Yes it is.

deadpool - 15-9-2014 at 15:35

Hello Nerds!

I've made Lead Azide several times with a supply of Sodium Azide that I've had for quite some time; however, my Sodium Azide supply is running low. Therefore, I've been trying to synthesis Sodium Azide from Hydrazine Sulfate; Isopropyl nitrite; and sodium hydroxide. Unfortunately I can't quite seem to get the end product (some documents refer using ethyl nitrite instead, but I think either will work please correct me if I am wrong). The documentation is not entirely clear, but the reaction doesn't seem to work or go to completion. I also know its possible to make Lead Azide directly from the Hydrazine Sulfate, but I'm not sure if I feel comfortable making it directly, but at this point I would be happy with any successful product.

Metacelsus - 15-9-2014 at 17:35

Please describe the procedure you use in more detail. In my experience, you need to prepare hydrazine hydrate (be careful!) before reacting it with the isopropyl nitrite and sodium hydroxide.

[Edited on 16-9-2014 by Cheddite Cheese]

roXefeller - 23-9-2014 at 17:54

As a general question, how do you all feel about the toxicity of the azide family? I've read a couple precautions about it so I'm appropriately concerned. I know most all EM are toxic but there is a difference between the liver toxicity of TNT and the pulmonary edema of NOx. While I'm not planning to eat it, what sorts of behaviors are peculiar in handling these materials and the hydrazine precursors?

Bert - 23-9-2014 at 22:04

Quote: Originally posted by roXefeller  
As a general question, how do you all feel about the toxicity of the azide family?


Similar to my feelings about the cyanide family?

Plus the whole primary explosive issue...

If you ingest, or expose azides to an acidic environment without a proper air handling scheme/respiratory protection in place... Expect to stop breathing soon after. Add to this an alarming tendency for random explosions of Hydrazoic acid, vapors of same and various materials exposed to these.

[Edited on 24-9-2014 by Bert]

goldenoranges - 25-9-2014 at 13:49

It says the video is private for me; link?

Ral123 - 28-9-2014 at 12:18

I'm very sorry for the video, I assure you it's value is almost entirely entertainment. Some TV has used material from the channel, let's say for their own frame of things :/