PETN

[stanfield]

In a forum about explosives, someone gave me this equation for PETN production :
C5H12O4 + 4 HNO3 => C5H8N4O12 + 4 H2O
Is it correct ? I'm suspicious because it's very different from Megalomai's synthesis once again...

and he said that there is many way to produce PETN :
KNO3/H2SO4
N2O5
(Ac)2O/HNO3
(TFAc)2O/HNO3
Pb(NO3)4/HNO3 <=
HNO3/HSO3F
HNO3/BF3
HNO3/P2O5
HNO3(100%)
HNO3 (70%)/NH2-CO-NH3NO3

What do you think of these synthesis ? Could you give me more information about Pb(NO3)4/HNO3 method if possible ?

And finally, have you tried to make PETN ? is it an "easy" preparation

thanx !

[vulture]

The reaction equation is correct. I can't tell you more, sorry.

I know N2O5 is a very strong nitrating agent, but it's difficult to make and to handle.

[stanfield]

ok but I found (if I remember correctly) 117 mL of 100% nitric acid ! Megalomania said 400 ml for 100 g of pentaerytritol ! What's is wrong ?

what's the name of N2O5 ?

I've heard about a synthesis of PETN wich include H2SO4, could it be better ? (H2S4 absord water producted by the reaction) What's the ratio for 100g of pentaerytritol ?

thanx for all !

[Mr Cool]

117g of 100% HNO3 might be the theoretical amount needed for 100g of PE. IIRC 400g per 100g of PE is about a triple excess, but roughly that amount is required to get a full nitration.
All those methods would probably work, although I've never seen lead tetranitrate. Maybe it's normal lead nitrate with HNO3 of crystalisation, rather than H2O of crystalisation trapped in the crystals.
The 70% HNO3 / urea nitrate method is unusual, anyone think it'd work?

Making PETN is very easy once you've got the 100% HNO3 and PE. It's quick, simple and the yields are high.

N2O5 is dinitrogen pentoxide.

The methods with H2SO4 are inferior to the one with 100% HNO3, apparently the product is more difficult to purify.

[stanfield]

ok, thanx and maybe a last question :
Some guys said that when you're adding the pentaerytritol, the temperature must be kept between 0 and 5 °C, another guys said around 20°C

who's right ? what's the influence of the temperature on the final product ? stability ?

any reply is more than appreciated

[Madog555]

hey, i would like to make that cap that i tested out storeable, so i decied to use lead styphanate extracted from primers for a primary.

can anyone tell me if a .22 of this will work for initiateing the PETN in my .223 cap?

also if anybody has any info on the properties of lead styphanate posting it would be greatly apreciated.

[stanfield]

PETN is very sensitive to detonators, so, one .22 long rifle cartdrige is very well...

[Madog555]

oh shit, im sorry i meant to post this in the detonator thread

and lead tetranitrate definately can exhist. The oxidation numbers for lead are 2 and 4, of course the most stable is 2, thats why you normaly only hear of lead dinitrate. so there definately can be a Pb(NO₃)₄
i just have no idea how the hell you can make it.

the

[ 07 March 2002: Message edited by: Madog ]

[Mr Cool]

If anyone's interested in making acetaldehyde for PE, I've done a few tests with ethanol + H2O2 to oxidise it, and K2Cr2O7 in catalytic amounts (very little is needed). I used 9% H2O2 and vodka (40%) because that's all I had at the time, and it was definitely making acetaldehyde. So this could be a promising method, especially if 95% ethanol and 30% H2O2 were used.

[Lagen]

Well this route seems to work, but... I used 95% ethanol and 30% H2O2 in stoichiometric proportion, 0.5 mol in a 150 ml beaker. The two didn't react for quite some time so I dropped in just two large crystals of K2Cr2O7. The solution turned purple, a gas started evolving and the mixture warmed up a tiny little bit. As I have already developed a sense for these situations, I quickly grabbed the beaker and ran to the bathroom. There I was waiting over a tub half full of cold water, the temperature was increasing gradually and at about 15 mins. of the mixing, I got a really hot beaker and a runaway. Apple smell is now escaping from the gutter. Obviously that small amount of dichromate could not have caused this, so the H2O2 must have reacted. But, I'd hesitate to put this stuff into a distillation setup...

[Lagen]

Obviously the purple color wasn't caused by any impurity (I used RG chems) but by the peroxochromate anion. The pH must have been acidic, and the peroxochromic acid decomposed with evolution of oxygen. But the resulting chromate was immediately converted by the excess H2O2, and so forth... So the gas might not have been acetaldehyde for the most part. (Although the evolution was tremendous there was only a faint smell of acetaldehyde, like apples, not irritant, so the concentration was low. Similar to my previous attempts with KMnO4, which produced only atrace of acetaldehyde and a lot of acetic acid.) Also, at the elevated temperature a lot of the H2O2 must have been decomposing thermally.

Obviously there must be some reasons why this method isn't recommended, maybe: Potassium dichromate as an oxidizing agent is stable at elevated temperatures, whereas H2O2 isn't. Surely there's a lot of byproducts with this method as well, so some separation will be necessary, like in the Rhodium synth. To avoid the decomposition of the H2O2, the distillation would have to be done at low temperatures, the acetaldehyde evolution would be slow and the distillation very inefficient. Also I'm not sure if the acetaldehyde vapours will be stable in an atmosphere of almost pure oxygen...

I'll try a little K2Cr2O7 in H2O2 to see if it decomposes in the same fashion. And I'll try again with ethanol and some NaOH to correct the pH...

[Yikes]

Who ever taught you to just throw all of your reagents in a reaction vessel, THEN add your catalyst?? :rolleyes:

IMHO, you should try to put the chromate and the ethanol in your reaction vessel, then slowly add (drip?) your H2O2 into it while stirring. (Or swirling the vessel.)

[Lagen]

Yikes, I'm tired of flaming so I'll keep it to the facts. You know, there's a lot of manuf. processes where you "throw your reactants and catalyst in the vessel" then create the necessary conditions for them to react (temp., pressure etc.), just browse a patent database. However, your note is irrelevant here, I knew that there were true catalysts for this job and that K2Cr2O7 wasn't one. Mr Cool's post just made me to try and make a demonstration. This is how the rest of it went:

I tried K2Cr2O7 in H2O2, it produced about the same result, only without the CH3CHO smell. So the reaction is mainly catalytic decomposition of H2O2 with K2Cr2O7. After the solution warmed up and started frothing, I added a pellet of NaOH. The color changed from purple-brown to yellow-orange of chromate. As expected, the mixture was much more stable, pH=10. With only slight cooling, the decomposition went on at a peaceful rate.

I added a little ethanol, and this time no CH3CHO smell was produced. About 30 minutes later I added slightly more ethanol, the solution turned cloudy and a light brown color. Some light brown precipitate formed, this doesn't dissolve in anything I tried on it. After 3 hours the precipitate turned orange, pH remained at 10, so no acetic acid was produced, and the mixture still smelt of ethanol. I have no clue what the precipitate could be, I'd guess chromium(II) acetate or an organic peroxide. After further 8 hours this precipitate dissolved and the solution turned light yellow (Na and K chromates). Still smells of ethanol so apparently this hasn't been oxidized, even though there was a large excess of H2O2 initially.

[rikkitikkitavi]

why not try the classic chromate + sulfuric acid oxidizing mixture, a classic in organic synthesis...

simply mix them, add ethanol and apply heat gently while distilling over acetaldehyde (BP 21 C).

/rickard

[Mr Cool]

The whole point of trying a new method was that chromates/dichromates are quite hard to come by, and with the traditional acetaldehyde synth., you need quite a lot of them if you want to make lots of acetaldehyde. But if something else could be used as the oxidiser, something cheap and common like H2O2, then acetaldehyde would be much easier and cheaper to make.