Sciencemadness Discussion Board - RDX synthesis

RDX synthesis

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underground - 1-4-2014 at 03:17

Quote: Originally posted by DubaiAmateurRocketry

^ RDX probably decompose in nitric acid which is whyyyy people use Ac2O and HNO3 for nitration of high yield.

What to you mean by "decompose in nitric acid"
You can make RDX with just 99%Nitric acid and Hexamine, without Ac2O

roXefeller - 2-4-2014 at 03:48

Quote: Originally posted by underground

I was wondering if RDX can be made by mixing H2SO4 with an excess of Ammonium Nitrate, so all of H2SO4 is going to react, to form pure HN03, and also the rest AN is also going to help the formation of RDX

The excess of NH4NO3 is useful because it makes up the nitrogen deficiency in hexamine. The 1951 Bachmann article mentions around 30% of RDX contains this supplemental nitrogen. They determined this by radioisotope N15 that the nitrate was made from.

But you need to distill the nitric acid away from the bisulfate. There is an equilibrium occurring within the bisulfate:
2HSO4 <--> H2SO4 + SO4
There's always acid lingering.

DubaiAmateurRocketry - 2-4-2014 at 07:19

Sorry I meant in sulfuric acid, typing mistake.

underground - 2-4-2014 at 07:37

Quote: Originally posted by roXefeller

Quote: Originally posted by underground

H2SO4 + NH4NO3 --> NH4HSO4 + HNO3
Not any bisulfate at all, if you just let all the AN to react with H2SO4, will not end with pure NH4HSO4 and HNO3.
Not any H2S04 to destroy the RDX, or bisulfate.

[Edited on 2-4-2014 by underground]

Bert - 2-4-2014 at 09:48

underground, DubaiAmateurRocketry, roXefeller:

You each have a piece of a puzzle correct.

And another you're missing, or an incorrect assumption.

I'm betting between the 3 of you, a good answer to underground's question can shortly be had-

Start here: Chemical reactions are reversible, and go to an equilibrium.

Write as clearly as you can, ballance reactions (and check that they are what happens in the real world!), provide links to where you found concepts.

I'll watch you figure it out.

Vikascoder - 2-4-2014 at 09:58

Quote: Originally posted by TheAlchemistPirate

This guy already showed a way.

Quote: Originally posted by lucifer

I’ve made rdx with distilled 99% HNO3 and with methenamine,
The Yeild wasn’t bad, 74% (29,7gr rdx out of 25gr methenamine).

I,ve changed the nitration time in meglomainia’s method, to get a better yeild.
(info from urbanski).

Well I have already read this post but I want to know the accurate process which uses hexamine dinitrare and concentrated nitric acid to make rdx

Slowly ad 25gr methenamine to the HNO3, which went quite easy keeping the temperature under 30degr C
After that put the solution in a water bath of 60 degr C, letting the temperature of the solution rise to 55 degr C Keep it at this temperature for 12 minutes.
Then cool it down in a ice bad to 20 degr C
During this phase some rdx becomes visible in the solution.
Let it stand for 10 min.
Then add to the solution 400 ml of ice water
A lot more of rdx will precipitatet out of the solution.
Let this solution stand for 5 minutes
After filtering neutralised the rdx with 400 ml 5% sodium bicarbonate solution.

The yeild after completely drying was 29.7 gr which is if I am ride about 74%

DubaiAmateurRocketry - 2-4-2014 at 10:04

You can not use H2SO4 because Hexamine decomposes in the presence of concetrated H2SO4 to form formaldehyde and ammonia. I dont know what Bert is trying to say.
http://dspace.upce.cz/bitstream/10195/42530/1/MartinkovaZ_De...

underground - 2-4-2014 at 10:53

Quote: Originally posted by Bert

underground, DubaiAmateurRocketry, roXefeller:

You each have a piece of a puzzle correct.

And another you're missing, or an incorrect assumption.

I'm betting between the 3 of you, a good answer to underground's question can shortly be had-

Start here: Chemical reactions are reversible, and go to an equilibrium.

Write as clearly as you can, ballance reactions (and check that they are what happens in the real world!), provide links to where you found concepts.

I'll watch you figure it out.

Bert as i said, it was an idea. The concept was from my mind.

Quote: Originally posted by DubaiAmateurRocketry

You can not use H2SO4 because Hexamine decomposes in the presence of concetrated H2SO4 to form formaldehyde and ammonia. I dont know what Bert is trying to say.

I know that Hexamine decomposes in the presence of concetrated H2SO4, that is why i said to use an excess of ammonium nitrate, to convert ALL of H2SO4 to HNO3. Here is the ballance reaction
H2SO4 + NH4NO3 --> NH4HSO4 + HNO3

So at the end you are going to have a mix of NH4NO3/HNO3/NH4HSO4.

So i can not see any reason why RDX is going to decompose as long as there is not any more H2SO4 (It has already be converted to NH4HSO4 and HNO3 with the presence of NH4NO3)

I hope that it is clear now.

VladimirLem - 2-4-2014 at 11:13

Quote: Originally posted by underground

So at the end you are going to have a mix of NH4NO3/HNO3/NH4HSO4.

....well...and you re going to nitrate hexamine with that crap?

its the same problem that you have at the K6 synthgesis...to make these compounds you need really pure/high quality chemicals...espechially cause the one step synthesis of hexamine needs a huge excess of HNO3 even if its 95%<...as i said, you could try this at making ETN but i guess you will waste expensive stuff at making RDX this way

Bert - 2-4-2014 at 12:59

Quote:

I know that Hexamine decomposes in the presence of concetrated H2SO4, that is why i said to use an excess of ammonium nitrate, to convert ALL of H2SO4 to HNO3. Here is the ballance reaction H2SO4 + NH4NO3 --> NH4HSO4 + HNO3 So at the end you are going to have a mix of NH4NO3/HNO3/NH4HSO4. So i can not see any reason why RDX is going to decompose as long as there is not any more H2SO4 (It has already be converted to NH4HSO4 and HNO3 with the presence of NH4NO3) I hope that it is clear now.

Clear. Understand exactly what you thought can happen, and why.

One of the best ways to find how well you've learned something is to try and teach it to someone else.

Who among you can explain clearly enough to underground WHY there is still going to be sulfuric acid present, or figure out what concept he need learn to understand?

Why are YOU being asked if you can explain such things?!

[Edited on 2-4-2014 by Bert]

underground - 3-4-2014 at 06:46

Quote: Originally posted by Bert

Quote:

I know that Hexamine decomposes in the presence of concetrated H2SO4, that is why i said to use an excess of ammonium nitrate, to convert ALL of H2SO4 to HNO3. Here is the ballance reaction H2SO4 + NH4NO3 --> NH4HSO4 + HNO3 So at the end you are going to have a mix of NH4NO3/HNO3/NH4HSO4. So i can not see any reason why RDX is going to decompose as long as there is not any more H2SO4 (It has already be converted to NH4HSO4 and HNO3 with the presence of NH4NO3) I hope that it is clear now.

Yea i understand. As roXefeller thried to explain, it is the equilibrium that it is going to occur, so always some H2SO4 will be in presence, that is why distillation it is necessary

TheAlchemistPirate - 3-4-2014 at 17:16

Earlier today I attempted to make nitric acid by nitrate salt and sulfuric acid distillation, but unfortunately, after I started adding sulfuric acid it started to immediately boil and make tons of nitrous oxide gas. I used nurdrage's method, here are the things I did:
1. I preheated a two-necked distillation flask to 120 degrees C (with all the distillation apparatus set up)
2. I added 40 grams of KN03
3. I started to add 80 milliliters of H2SO4, but it started to start making NOx gasses, so I turned off my hot plate and sealed the opening.
It is now sitting in my garage, Im going to clean it tomorrow. Could someone tell me what I did wrong? In videos it didn't react early as fast.

[Edited on 4-4-2014 by TheAlchemistPirate]

Zyklon-A - 3-4-2014 at 17:34

Don't preheat it.

TheAlchemistPirate - 3-4-2014 at 17:55

Doesn't it make nitric acid when not heated? What if I preheated it to a lower temperature? One not high enough to make large amounts of nitrous oxide gas?

Oh yeah. NOx.

Bert - 3-4-2014 at 18:27

If you keep your Sulfuric acid in a freezer, adding the nitrate is a LOT less exciting...

[Edited on 4-4-2014 by Bert]

TheAlchemistPirate - 3-4-2014 at 18:30

I mean preheat it to a low temperature at first then after I pour it in, raise the temperature.

Zyklon-A - 3-4-2014 at 18:32

You heat it only after you add the reagents in the flask, to distill it. you don't want the reaction to happen until everything is in the controlled flask.
Keep the flask at RT (or below) until everything is inside and you are ready to distill.

[Edited on 4-4-2014 by Zyklonb]

TheAlchemistPirate - 3-4-2014 at 18:46

Oh, I didn't know that I had to cool it. I never saw a tutorial mentioning that, and I have researched this procedure for weeks. Thanks for replying, btw nothing was damaged, and I left the area for a while to let the gas escape to outside ( I live in a remote area )

DubaiAmateurRocketry - 4-4-2014 at 00:49

Why would one heat it? If you add KNO3 to sulfuric acid slowly and control the temperature, you would be fine. HNO3 boils at around 80 degree Celsius, therefore as bert said, adding KNO3 to sulfuric acid that was kept in a freezer sounds like a very good idea. Have any one tried freezing the KNO3 too? does it help?

TheAlchemistPirate - 4-4-2014 at 13:21

I thought that distilling the KNO3 and the H2SO4 would be better than simply adding the two chemicals together while they are cold, for the following reasons:
1. Better purity
2. Better yield
3. Higher concentration
4. less dangerous
I did run into a problem today though, after washing the equipment I noticed that the ground glass stopper in my two-necked boiling flask was stuck. I noticed small crystallization between the glass. I heard this happens when you don't apply vacuum grease to the joints, but I did apply it and all my other joints were fine. Is there a simple way to get the stopper off?

Zyklon-A - 4-4-2014 at 16:08

Heat it up with a heat gun or similar device. The outer joint will expand slightly, and before the inner joint.

Bert - 4-4-2014 at 16:40

Heat gun doesn't work super well-

Best bet is soak a liquid into the joint, if you use heat it has to be FAST and tightly focused.

See here: http://onlinelibrary.wiley.com/store/10.1002/9780470141045.a...

TheAlchemistPirate - 4-4-2014 at 16:56

I am heating the flask in boiling water right now, I will take it out in a few minutes. That link doesn't want to work with my computer for some reason, sorry for going completely off topic. UPDATE: The boiling water did nothing,not sure why I thought thatd work. I am now freezing the flask, tomorrow I will use a propane torch on the female joint and try to pull out the male one...

[Edited on 5-4-2014 by TheAlchemistPirate]

Bert - 5-4-2014 at 05:54

Try a penetrating solvent capable of dissolving grease & displaceing water before whipping out the torch, working glass with heat is an art learned over a big pile of busted glass in my experience!

I bought a used vacuum dessicator with a totally frozen valve, grease had turned to rock. Soaking the frozen joint over night with Kano "Kroil" allowed me to get it apart easily the next day.

Don't be in a hurry... You can always break it later of you want!

TheAlchemistPirate - 5-4-2014 at 12:56

Ok, Im now soaking it in a high-power grease remover. I made sure to check this thread before I tried heating it. Also, could someone answer my question about the efficiency of directly adding cold H2SO4 to KNO3?

DubaiAmateurRocketry - 5-4-2014 at 14:02

Quote: Originally posted by TheAlchemistPirate

Ok, Im now soaking it in a high-power grease remover. I made sure to check this thread before I tried heating it. Also, could someone answer my question about the efficiency of directly adding cold H2SO4 to KNO3?

When you have a right amount of moles for the conversion, then theoretically, all KNO3 and H2SO4 will result in K2SO4 and HNO3. The cold H2SO4 does not matter.

H2SO4 + 2 KNO3 > K2SO4 + 2 HNO3

Bert - 5-4-2014 at 14:18

High powered grease remover? What's that... Sodium hydroxide? Non polar solvent? Carbon tetrachloride (That would be cool! Save me some if it is...) MSDS is probably on line.

WD-40 would be my first choice of common household chemicals to free a stuck ground glass joint.

If you did manage to get some water inside the joint (you boiled the whole thing!) and then heat the glass above boiling point of water with a torch, be aware: glass is very strong against compression, but not so good against tension. Like the kind of tension boiling water with no way for steam to escape makes? KA-CHINK!!!

About the cold Sulfuric acid question? Check your PM's.

TheAlchemistPirate - 5-4-2014 at 16:01

I used an industrial (supposedly high strength) cleaner called purple power.If this doesn't work I will try WD-40 , but I did notice some of the crystals were gone after 3 hours. I will keep trying and I wont try to open it with heat.

NeonPulse - 5-4-2014 at 16:59

Wd40 worked for me. I had a thermometer adapter stuck fast to my condenser. During my 1st HNO3 distillation a joint popped and got some of the nitric on the joint, I did not use enough grease and just pushing it back on hard the heat made it stick hard.
Heating failed to free it but after trying various solvents the WD40 soaked right in and pop, it was finally free. I later broke the jacket inlet on it anyway..... You can also buy a separator which works kind of like a vise but I guess if you only have one frozen joint why bother.

TheAlchemistPirate - 5-4-2014 at 17:38

That's what happened to me too, neonpulse. I just put the spray WD-40 on the the flask, I also tried a back massaging vibrator thing. Did you guys use a more liquid-like WD-40? I have seen several methods here that I have been trying on this site all day https://groups.google.com/forum/#!topic/sci.chem/GF1H4eRwYVc . Maybe I should have more patience...

underground - 7-4-2014 at 03:09

Wich way has the best yields for making RDX with homemade distilled Nitric Acid and without the use of any dehydrating agents like Ac2O/N2O5 e.t.c ? Also will NH4NO3 increase the yields, or it is not nessesary if your nitric acid is going to be clear (bubble air through Nitric acid to remove any dissolved Nitrogen dioxide) ?

Bert - 7-4-2014 at 05:09

You have read the whole RDX thread this question is posted in? Or other materials on other sites? DOCUMENT.

You have seen there are a LOT of different synthesis of this chemical? And you are confused as to which is "best"? By "best", do you mean highest yield for ammount of strong nitric acid used, or of hexamine? Or purest product? Least equipment needed? Fastest?

underground - 7-4-2014 at 07:11

Quote: Originally posted by Bert

You have read the whole RDX thread this question is posted in? Or other materials on other sites? DOCUMENT.

You have seen there are a LOT of different synthesis of this chemical? And you are confused as to which is "best"? By "best", do you mean highest yield for ammount of strong nitric acid used, or of hexamine? Or purest product? Least equipment needed? Fastest?

Al long as here the Nitric acid is the most difficult chemical to prepare, i mean the highest yields for ammount of strong nitric acid used.

Bert - 7-4-2014 at 11:29

Quote: Originally posted by underground

Al long as here the Nitric acid is the most difficult chemical to prepare, i mean the highest yields for ammount of strong nitric acid used.

OK! That makes your question clear to me.

I know exactly where to find the information. It's right here on sciencemadness.org forum.

A number of others know where it is too.

But you are neglecting to do something.

Something that is written in the site guidelines.

Something that I've said is required as part of a properly asked question. Repeatedly.

I am not going to spoon feed you a "cook book recipe" or a link to something containing these.

I will maintain the site policies and close, delete or move such posts and threads I see whose content is not proper or to site standards. I may give tips on how one proceeds to research topics to people who are seriously TRYING but ignorant. I will ALLWAYS give safety information if I see something bad is likely to happen from a post.

But it's up to each person to research a topic and follow site standard form to communicate about it. Not going to behave as a professional? Professionals won't find you worth spending time over, not for free anyhow.

underground - 7-4-2014 at 17:44

It has been discussed here by Rosco Bodine that Mg(NO3)2 can be used as a dehydrating reagent, like H2SO4, so i was wondering if anyone have ever tried Mg(NO3)2 as a substitute of AcO2 for making RDX.

[Edited on 8-4-2014 by underground]

Dornier 335A - 7-4-2014 at 23:25

A quick search revealed this patent: Method for synthetizing cyclotrimethylenetrinitramine employing magnesium-nitrate-assisted direct nitration process
They used 12 times as much 95% HNO₃ by mass as hexamine, and the molar ratio of Mg(NO₃)₂*6H₂O to hexamine was 1 to 2. They ran the nitration at 30°C for an hour and reported slightly better yield than for the traditional procedure.

roXefeller - 8-4-2014 at 05:49

Quote: Originally posted by Dornier 335A

A quick search revealed this patent: Method for synthetizing cyclotrimethylenetrinitramine employing magnesium-nitrate-assisted direct nitration process
They used 12 times as much 95% HNO₃ by mass as hexamine, and the molar ratio of Mg(NO₃)₂*6H₂O to hexamine was 1 to 2. They ran the nitration at 30°C for an hour and reported slightly better yield than for the traditional procedure.

That same thread where underground got the Mg(NO3)2 concept from also has relevant discussion from Rosco (http://www.sciencemadness.org/talk/viewthread.php?tid=4701&a...). Using 12:1 by mass HNO3 to hexamine is wasteful of acid (Rosco thinks it can be done with 100ml HNO3: 40 g HDN, or ~8.3:1 acid:hexamine by mass). It was discussed that the yield was dependent on final reaction temperature. So it seems the patent authors increased the HNO3 to compensate for the 30C reaction. BTW that patent just seems odd. Why are they using a hexahydrate to dehydrate? And why are they writing new patents on a 70 year old process (direct nitration of hexamine from HNO3)? As far as trying Mg(NO3)2 to dehydrate, go ahead, someone has to put patents to practice. You should probably dehydrate the salt first. But you should keep in mind other concepts that reduce the acid use, detailed in that RDX thread, such as urea nitrate stabilized decomposition at high temps, and ammonium nitrate supplementation. And you should read Bachmann's work. He suggests varying cleaving mechanisms of hexamine depending on temperatures and dilutions, which result in different paths to the nitramine.

hissingnoise - 8-4-2014 at 06:07

Quote:

Why are they using a hexahydrate to dehydrate? And why are they writing new patents on a 70 year old process (direct nitration of hexamine from HNO3)? As far as trying Mg(NO3)2 to dehydrate, go ahead, someone has to put patents to practice. You should probably dehydrate the salt first.

The anhydrous salt is hydrated by dilute acid and cannot be dehydrated, decomposing to the oxide and NO₂ + O₂ on heating . . .

caterpillar - 8-4-2014 at 13:10

What about Ca(NO3)2 ? This salt is stable up to few hundreds Celsius and can be dehydrated without problems. And the best way to use smaller amount of nitric acid is to use hexamine dinitrate instead of hexamine. Moreover, this preparation is not very sensitive to NOx, presenting usually in concentrated nitric acid. I made RDX twice- few grams only, but quite successfully.

Bert - 8-4-2014 at 14:07

I intend to split off the nitric acid production side trip right about here, and graft it onto a nitric acid thread (or shuffle some of it off to beginnings, as appropriate). It's going to take me a bit to work that out-

My apologies to all, I should have been more proactive on this earlier. And my thanks to those who have followed the site standards when posting

Keep it on RDX, document sources & concepts and it stays...

It is okay to be ignorant when first arriving and posting. However, you must be willing to make an effort to learn. If you are unable to cite references in support of an idea or as background to your question, the post belongs in Beginnings. Questions that provide background information and show effort are more likely to receive good responses. If an existing thread covers the topic you're about to post about, post in that thread instead of a new one. It makes it easier for members to keep up with topics of interest. You may need to search before posting if you're unsure whether or not a thread already exists. The search engine is not very powerful and may miss relevant threads, but please make at least a cursory effort.

roXefeller - 8-4-2014 at 14:26

Quote: Originally posted by hissingnoise

The anhydrous salt is hydrated by dilute acid and cannot be dehydrated, decomposing to the oxide and NO₂ + O₂ on heating . . .

I can only reference Rosco's post to support the claim that Mg(NO3)2 can be dehydrated.

Quote:

If it is wished to make the magnesium monohydrate separately , so as to avoid any consumption of acid in its formation , simply long boiling of MgO with ammonium nitrate
to a cessation of evolution of ammonia should result in
a solution of Mg(NO3)2 . Heating this to dryness and then
to 330C produces the monohydrate .

underground - 9-4-2014 at 02:10

Quote: Originally posted by roXefeller

Yea that is true, it looks like a 70-80% yield of RDX can be achieved only with only 21ml of acid and 7gr of HDN.

Also it looks like Urea nitrate and Ammonium nitrate really does not help at all, and it would be better to not use them, just only HNO3 and HDN

Quote: Originally posted by Boomer

Update: made another batch of nitric (250ml) and tried the first/last fraction for RDX. This is in colour between WFNA and RFNA, hence I call it WTFNA
(what-the-fuck nitric acid, i.e. I dont care). The *same* batch and bottle had given me 80% instead of 92% yield for MHN, and similar batches
preciously 30-40% only for RDX using the 1:2 ratio. And now comes the surprise:

7g of HDN where treated like above, using 21ml of the 'bad' acid, and letting it react for 20 min at 60 +/2 C. Result was 4.75g or 81%.
So a 1:3 ratio will forgive less-than-perfect nitric. It was dark yellow and had a density of 1.515 at -4C (or was it 0C? See above).
Makes d=1.48 at RT, from memory, is that 90% HNO3 considering the NOx content?

Also caterpillar that one it sounds really interesting, that one i was thinking also but they said that an equilibrium is going to occur and H2SO4 is going to be in presence, destroying the RDX. But it looks like with your method it can be done. Maybe with higher temperatures we can drive the reaction forward and stop the formation of H2SO4

Quote: Originally posted by caterpillar

What about Ca(NO3)2 ? This salt is stable up to few hundreds Celsius and can be dehydrated without problems. And the best way to use smaller amount of nitric acid is to use hexamine dinitrate instead of hexamine. Moreover, this preparation is not very sensitive to NOx, presenting usually in concentrated nitric acid. I made RDX twice- few grams only, but quite successfully.

[Edited on 9-4-2014 by underground]

hissingnoise - 9-4-2014 at 02:27

Quote:

I can only reference Rosco's post to support the claim that Mg(NO3)2 can be dehydrated.

Quote:

From Wiki;

Since magnesium nitrate has a high affinity for water, heating the hexahydrate does not result in the dehydration of the salt. Instead, magnesium nitrate hexahydrate decomposes into magnesium oxide, oxygen, and nitrogen oxides.

2 Mg(NO3)2 → 2 MgO + 4 NO2 + O2

The absorption of these nitrogen oxides in water is one possible route to synthesize nitric acid. Although it is inefficient, it does not require the use of another strong acid.

Anhydrous magnesium nitrate is also used to increase the concentration of nitric acid past its azeotrope of approximately 68% nitric acid and 32% water. It is also occasionally used as a desiccant.

The decomp. temp. is given as 330°C!

DubaiAmateurRocketry - 9-4-2014 at 02:51

Quote: Originally posted by hissingnoise

Quote:

Anhydrous magnesium nitrate is also used to increase the concentration of nitric acid past its azeotrope of approximately 68% nitric acid and 32% water. It is also occasionally used as a desiccant.

The decomp. temp. is given as 330°C!

Does that mean you can concentrate nitric acid simply with magnesium nitrate(anhydrous) ?

hissingnoise - 9-4-2014 at 06:14

Yes it does, and it is sometimes used in recovery of spent acids but sulphuric acid is convenient for the amateur in that it's a more potent dehydrant and may be reconcentrated for further use . . .

roXefeller - 9-4-2014 at 12:27

Quote: Originally posted by underground

Also it looks like Urea nitrate and Ammonium nitrate really does not help at all, and it would be better to not use them, just only HNO3 and HDN

A selection from Bachmann:

Quote:

In view of the nitrolysis of hexamine to RDX
(one mole) by nitric acid alone, it might be expected
that if the ammonium nitrate were omitted from
the present reaction mixture at least one mole of
RDX would be formed. This is not the case.
Instead, the reaction takes an entirely different
course to yield the linear trinitramine IV as described
below, and only small amounts of RDX
are produced. The result showed that the ammonium
nitrate serves not only as the source of the
two nitrogen atoms required for the second mole
of RDX but is essential in directing the course of
the nitrolysis to form the first mole of RDX.

another

Quote:

The resultant mixture of RDX
crystals (d. 1.77) and HMX crystals (d. 1.96) was separated
into three fractions by repeated fractional centrifugings in a
mixture (d. 1.81) of trimethylene dibromide and mineral oil.
One fraction consisted of RDX with m.p. 197-200°, which
after two recrystallizations from acetone had m.p. 204-
205' (cor.) and contained 3.0 atom per cent. of N15. Another
fraction was chiefly HMX with m.p. 268-269', which
was raised to 282" (cor.) after two recrystallizations from
acetone; atom per cent. N15 based on total nitrogen, 1.5%.
The recovered ammonium nitrate, which was purified by
recrystallization to constant m.p. 168.5-169.5', contained
3.95 atom per cent. of N15 (original tracer salt had 7.5
atom per cent. of N15, based on the two N atoms).

Naturally occuring N15 isotope is 0.4%.

And from the Hodgson text:

Quote:

The nitrolysis of hexamine is a direct route to the military high explosives 1,3,5-trinitro-
1,3,5-triazacyclohexane (RDX) and 1,3,5,7-tetranitro-13,5,7-tetraazacyclooctane (HMX).1,46
The direct nitrolysis of hexamine with dinitrogen pentoxide in absolute nitric acid provides
RDX in 57% yield.54 RDX prepared by this process is exceptionally pure, but other reagents,
like ammonium nitrate–nitric acid–acetic anhydride, give much higher yields, partly because
they use ammonium nitrate to supplement for ammonium nitrogen deficiency in the reaction.

another

Quote:

An unusual feature of the KA-process is that the reaction is conducted at 60–80 ◦C. Solutions
of nitric acid in acetic anhydride are known to be prone to dangerous ‘fume off’ at temperatures
above ambient. However, a saturated solution of ammonium nitrate in fuming nitric acid can be
added to warmed acetic anhydride without such danger. In fact, these reactions are commonly
conducted at 60–80 ◦C as a matter of safety by preventing a build-up of unreacted starting
material.

While not fully informative of the high temp reaction, it does lend to a stabilizing aspect.

As far as urea nitrate, I'll have to look in my references further. But you should really be doing that also. You can't depend solely on forum postings for your experiments. Like the Bible, they are open to misreading/misinterpretation of the author's intended concept. Or a lack of understanding of the conditions underwhich the author observed. You have to triangulate from multiple sources. You are seeking a truth that isn't necessarily fully documented.

Attachment: cyclic and linear nitramines.pdf (726kB)
This file has been downloaded 725 times

[Edited on 9-4-2014 by roXefeller]

NeonPulse - 18-4-2014 at 17:30

So i did finally get around to attempting a synthesis of RDX. it was a fairly sucessful attempt yeilding 19.3g dry RDX from 95ml HNO3 and 40g hexamine dinitrate. ithe acid was incorrectly measured though as i used the wrong measuring beaker (doh!) so i doubt it was the full 100ml. but anyway i did recrystallize it from acetone and got two nice clean crisp white crops sparkling RDX crystals. leaving the acetone to evaporate, the next night after work i was surprized to see these rather large crystals in the bottom of the beaker somewhat like broken glass, these were many, many times bigger than the first crops i got and hardly any of the acetone had evaporated. my question is: firstly are these crystals dangerous? like being prone to detonate due to internal stresses like some energetics?
i2: is it normal to grow rdx crystalls this size?
how big can they actually get if left to grow?

Napolean Dynamite - 18-4-2014 at 18:14

I wouldn't hammer them trying to break them apart, or grind them up in pestle and mortar. They probably aren't very usable in large crystal form, redissolve in minimal acetone and then dump this in 10x amount of cold water for fine powdery substance. Other than that I too am curious too know if large crystals are more sensitive, I would not worry much about handling the larger crystals.

Those crystals are very cool though

[Edited on 19-4-2014 by Napolean Dynamite]

VladimirLem - 18-4-2014 at 22:50

Quote: Originally posted by NeonPulse

RDX crystals

hell yeah

Bert - 19-4-2014 at 05:13

[Edited on 19-4-2014 by Bert]

Dany - 19-4-2014 at 09:19

Quote: Originally posted by NeonPulse

So i did finally get around to attempting a synthesis of RDX. it was a fairly sucessful attempt yeilding 19.3g dry RDX from 95ml HNO3 and 40g hexamine dinitrate. ithe acid was incorrectly measured though as i used the wrong measuring beaker (doh!) so i doubt it was the full 100ml. but anyway i did recrystallize it from acetone and got two nice clean crisp white crops sparkling RDX crystals. leaving the acetone to evaporate, the next night after work i was surprized to see these rather large crystals in the bottom of the beaker somewhat like broken glass, these were many, many times bigger than the first crops i got and hardly any of the acetone had evaporated. my question is: firstly are these crystals dangerous? like being prone to detonate due to internal stresses like some energetics?
i2: is it normal to grow rdx crystalls this size?
how big can they actually get if left to grow?

There is nothing to fear about single crystal RDX. Single crystal explosive have the highest possible Theoretical Maximum Density (TMD) thus the highest detonation velocity compared to other RDX form (e.g., RDX powder). The sensitivity of single crystal RDX is far low then the powdery form of the same explosive for a simple reason: single crystal RDX are voidless and contain no structural defects while powdery RDX contain many voids and possibly other solid impurities. When subject to a shock wave, the voids (and other impurities) in powdery RDX will act as hot spot, concentrating the shock energy around their structure via adiabatic compression or other hot spot formation mechanism (e.g, internal shear, jetting, friction [1], etc...). The reaction start at these hot spot and shock wave from each hot spot coalesce to form the detonation wave. Since single crystal explosive are lacking hot spot site, it is more difficult to initiate these explosive, so you need a more powerful shock wave to be able to initiate detonation. Another beautiful example is the one given in paragraph entitled :"Hot Spots and Transverse Waves" which can be found in [1]. The author is talking about powdery PETN and single crystal PETN. Experimental shows that powdery PETN (pressed to almost TMD) can detonate when subjet to a shock wave of 2.5 GPa (or 25 kbar) while a single crystal PETN need a 11 GPa (110 kbar) to detonate the reasons are the same for the example of RDX given above.

For the case of lead azide were spontaneous explosion have been seen in single crystal, the reason of this is not entirely an internal stress of crystal. Other reason exist but poorly understood.

Reference:

[1] William C. DAVIS, High explosives-the interaction of chemistry and mechanics (LOS ALAMOS SCIENCE).

Dany.

[Edited on 19-4-2014 by Dany]

VladimirLem - 21-4-2014 at 01:37

Hi guys...

could it be possible to "grow" explsoives crystals into special shapes?

exmple: dissolving ETN into warm-hot (below meltingpoint of the explosive) ethanol/aceton and then filling the sollution into some shaped charge container and letting the crystals gorw when putting that into a freezer?

when making ammoniumnitrate and "recystalize" it at a cold place it has exactly the shape of the container and a really high density, so could that work at other HEs? (ETN, PETN, RDX...)
if that would work, there where no need for phlegmatised/plastic/cast explosives anymore and the possiblity for getting the max density seems pretty good (only some percents [how many?] of solvent left)

Vlad

Dany - 21-4-2014 at 02:54

Quote: Originally posted by VladimirLem

Hi guys...

could it be possible to "grow" explsoives crystals into special shapes?

exmple: dissolving ETN into warm-hot (below meltingpoint of the explosive) ethanol/aceton and then filling the sollution into some shaped charge container and letting the crystals gorw when putting that into a freezer?

when making ammoniumnitrate and "recystalize" it at a cold place it has exactly the shape of the container and a really high density, so could that work at other HEs? (ETN, PETN, RDX...)
if that would work, there where no need for phlegmatised/plastic/cast explosives anymore and the possiblity for getting the max density seems pretty good (only some percents [how many?] of solvent left)

Vlad

yes it is possible to grow explosive crystals in special shape. This is done by recrystallizing the explosive using different solvents. This will led to different shape/polymorphs being produced. See this effect for the production of different HMX polymorphs

What is not possible is to grow single crystal explosive to a dimension suitable for shaped charge. Although you mentioned that NH₄NO₃ has the shape of the container and seems like it is homogenous, this is not true. At macroscopic scale the materials will look as if it was homogenous, but at the microscopic scale the material is non-homogenous but heterogeneous (polycrystalline) in nature. This is due to the method of precipitation/recrystallization and to the temperature gradient encountered in the layer of explosive during cooling which led to polycrystalline material. The best method in shaped charge to achieve the highest density materials is by casting the explosive (e.g., Octol) into the shape charge body or by making the explosive into a Plastic Bonded Explosive (PBX). PBX are known to achieve high density approaching 99% Theoretical Maximum Density (TMD).

Dany.

Motherload - 21-4-2014 at 10:26

If one really wants to use a single crystal ..... Grow one that is oversize using a seed crystal. And machine it to your needs with the proper safety precautions.
All that work just seems unnecessary when you can achieve 99% ... As Dany mentioned, using PBX.

simply RED - 21-4-2014 at 11:06

It is not bad to be mentioned that the vast majority of manufactured shaped charges are made by using pressed explosives like 95% RDX/HMH 5% wax, thermoplastic polymer, etc. Plastic bonded explosives are almost never seen, except in improvised devices. Casting (by melting or using polymers) is also increasingly rarely encountered, except in high caliber devices.

Pressed explosives provide very high percentage nitramine load that is impossible to achieve in any other way.

[Edited on 21-4-2014 by simply RED]

Dany - 21-4-2014 at 11:40

Quote: Originally posted by simply RED

It is not bad to be mentioned that the vast majority of manufactured shaped charges are made by using pressed explosives like 95% RDX/HMH 5% wax, thermoplastic polymer, etc. Plastic bonded explosives are almost never seen, except in improvised devices. Casting (by melting or using polymers) is also increasingly rarely encountered, except in high caliber devices.

Pressed explosives provide very high percentage nitramine load that is impossible to achieve in any other way.

[Edited on 21-4-2014 by simply RED]

What do you mean by improvised device??? PBX are special type of composite explosive which requires a high level of knowledge in manufacture. PBX are used in high performance shaped charge or Explosively Formed Projectile. One example is the PBX called LX-19. LX-19 is composed of 95.8 wt. % CL-20 (Hexanitrohexaazaisowurtzitane) and 4.2 wt. % Estane binder [1]. It is one of the best PBX known for shaped charge design.

I should also mention that plastic explosive (e.g., C-4) is also desirable in shaped charge because it is easy to load and to shape the explosive into the shaped charge body. However, plastic explosive do not offer the highest density of an explosive materials so their use may be limited where high performance are required. Liquid explosive, have also been used because they offer a homogenous medium, so a non-disturbed detonation wave can be expected from liquid explosive. It is well known that the symmetry of the detonation wave is critical when the latter interact with the liner. this can be achieved via liquid explosives. It is difficult to make perfectly homogenous solid explosive inside a shaped charge body. Any air cavity or density gradient in the explosive body will affect the detonation wave and the collapsing of the metal liner which may degrade the overall performance of the shaped charge

Reference:
[1] Murphy, M.J.; Baum, D.; Simpson, R.L.; Monoto, J.; Montesi, L.; Newman, K.; Tuerpe, D.; Osborn, J., Demonstration of enhanced warhead performance with more powerful explosives-UCRL-JC--127575.

Dany.

[Edited on 21-4-2014 by Dany]

simply RED - 22-4-2014 at 00:57

Dany, exactly! LX-19 is exactly "a PRESSED solid explosive formulation containing 95.2% by weight
epsilon phase 2,4,6,8,10,12-hexanitrohexaazaisowurtzitane (HNIW) and 4.8% Estane binder".

http://www.osti.gov/scitech/servlets/purl/105039

Of course it is plastic bonded but it is formed by pressing and not by casting. This is completely different class of explosives than cast-polymer bonded or "plastic" ones. Plastic explosives are never going to be found in anything other than improvised devices because of their poor mechanical properties and high sensitivity in case of extreme acceleration (and often rotation) that munitions endure!!!! 100% of all "eastern" made shaped charges munitions are press loaded and speaking from the literature, a very high percentage of the western ones are press loaded too.

""""It is not bad to be mentioned that the vast majority of manufactured shaped charges are made by using pressed explosives like 95% RDX/HMX 5% wax, thermoplastic polymer, etc."""" in this case 95% Cl-20 and 5% thermoplastic polymer.

[Edited on 22-4-2014 by simply RED]

Dany - 22-4-2014 at 01:25

The debate here is not about pressed or not. Of course LX-19 can be used as a pressed explosive but it's defenition is a PBX, not a plastic explosive ( PBX explosives can be made by pressing, casting or by injection moulding. Plastic explosive are made to be soft and moldable like C-4 or PE-4 explosive. I'm clarifying the situation because you said that PBX are used in improvised shaped charge which in my knowledge is not possible because pressing a PBX to almost 99% TMD require special techniques that are beyond the capability of an average pyroman (a good review on techniques used in PBX pressing can be found in the book of Paul COOPER, Explosives Engineering). PBX explosive is used in almost all high performance shaped charge and warheads. The Tomahawk missile for example uses the the PBXN-107 explosive (the N in PBXN is for Navy).

beautiful pictures and informations on tomahawk missile can be found here.

Dany.

[Edited on 22-4-2014 by Dany]

PHILOU Zrealone - 22-4-2014 at 01:29

Quote: Originally posted by VladimirLem

With the very low mp of ETN, it would be more easy to melt it externallly with hot water and allow it to harden slowly. Most of the time there is some contraction of the media while cooling so an open cylindrical recipient filled with a molten stuff usually will have an incurved U or V surface shape at the upper side in contact with the air.

The idea with the solvents is less good because in a recipient you have walls and this will prevent the evaporation of the solvents...what could only escape via the open side...this side will by the way harden faster and the rest below will remain "wet" much longer following a gradient of "wetness".The unevaporated solvent will have to travel the all material to be able to escape by the open side which upon time becomes harder to travel through owing to increased viscosity/hardening.

In the case of sensitive explosive; the bigger the cristals, the higher the risk of inner cristaline stress and sensitivity to shock and friction...if the cristals are growing in a closed recipient the walls will restrict their grow and favourise breaking/anomaly in the cristal partern...what means stress. The cristals will also be limited by other cristals and interpenetrate increasing friction sensitivity. Last but not least, the cristals will usually make voids between them so density might be less than finer powder filling and pressing.

Jimbo Jones - 22-4-2014 at 02:02

Quote: Originally posted by Dany

PBX explosive is used in almost all high performance shaped charge and warheads.

Dany.

[Edited on 22-4-2014 by Dany]

Quite a bold statement.

simply RED - 22-4-2014 at 02:52

Improvised shaped charges are often made with plastic and not "polymer bonded" explosives, type mistake.

Manufactured (low caliber <130 mm) shaped charges are pressed because the cast formulations require (too much) at least 12% polymer. AFAIK no russian shaped charge design uses polymers! They use A-9-1, okfol etc. mostly (95-5) - that substitute the polymers with parafines and ceresine. But parafine is also a polymer, it is low molecular mass, low melting point polyethylene! So things can get confused in some point...
Being all PBX, pressed and cast formulations are completely different and are manufactured using completely different machines in the factories. I do not see a reason why amateurs can't make cast formulations! I've done it numerous times! Pressed formulations on the other hand are not available for the amateurs as special machinery is needed for them to be manufactured.

Dany - 22-4-2014 at 02:56

Quote: Originally posted by Jimbo Jones

Quite a bold statement.

The Truth, The Whole Truth, and Nothing But The Truth

Dany.

Jimbo Jones - 22-4-2014 at 03:04

Quote: Originally posted by Dany

Quote: Originally posted by Jimbo Jones

Quite a bold statement.

The Truth, The Whole Truth, and Nothing But The Truth

Dany.

OK Dany. OK.

Dany - 22-4-2014 at 03:33

Here's a quote that prove that PBX are widely used in army's weapons were high performance is required, from [1]:

"Polymer bonded explosives based on hexogene or octogene, aluminium and polymer binder (PBX) fall into castable secondary explosives. Besides decreased detonation wave parameters, they are characterised by relatively slower delivery of energy in the detonation process and longer positive impulse phase. These explosives are used for the laboration of warheads with strong blast effect, such as main charge explosives for Navy underwater weapons (mines, torpedoes, bombs) and missile warheads"

Reference:

[1]Gordana Antić, Vesna Džingalašević, Milena Stanković, Zoran Borković, Explosive Characteristics of Cast PBX Based on HMX, AmmoniumPerchlorate and Aluminium, Scientific Technical Review,Vol.LIV,No.3-4,2004.

Dany.

[Edited on 22-4-2014 by Dany]

VladimirLem - 22-4-2014 at 09:29

Quote: Originally posted by Motherload

If one really wants to use a single crystal .....

no not exactly one crystal...when cooling down ammoniumnitarte, then you can see large needles [Picture1] (around 1.5cm*0.4cm*10cm<

filling the container up to the sollution is completely filled with crastyls and become a hard crystal block [Picture2]

so im talking about a high dense HE-crystalblock

@ the other guy with the -ETN melting idea-
ETN was just an example and im not gonna melt that shit

@the guys saying PBX:
well how can i know that the explosive is pressed enough? and HOW can i see that i should stop pressing

cause some HEs tend to get "dead-pressed" (extremely hard to ignite) and others may detonate when pressed to hard

lol
i dont know if pressing an HE is the way i should go since i dont habe professional equipment for that :-/

Vlad

simply RED - 22-4-2014 at 09:58

You can not do pressed, but you can do cast. Just cast it with HTPB binder for amateur rocket engines and you know it is okay

. RDX and PETN will not get dead pressed even if you cast under deep vacuum!

[Edited on 22-4-2014 by simply RED]

VladimirLem - 23-4-2014 at 07:19

Quote: Originally posted by simply RED

You can not do pressed, but you can do cast. Just cast it with HTPB binder for amateur rocket engines and you know it is okay

. RDX and PETN will not get dead pressed even if you cast under deep vacuum!

[Edited on 22-4-2014 by simply RED]

yeah, of course i could...i just wonder if this way i said could work

would be very easy to get high dense without much work

biggest doubts i have are if the detonation wave could be infuluenced by the different cristallayers in those HE-Block so that the detonatiopnwave would act different than cast/pressed (some uniform det.-wave is very important for shaped charges, you know)

Ral123 - 29-4-2014 at 08:22

Am I the only one here who wonders why the 95/5 material/phlegmatizer compositions aren't using TNAZ or TNT instead of wax? It would allow HMX based composition to reach similar performance and stability to CL-20 composition. I've read CL-20 is significantly more sensitive then RDX/HMX.

Dirty RDX synthesis

Ral123 - 29-4-2014 at 08:42

In my observation non recrystallized, washed only RDX is many times more stable then ETN, NG, Tetryl- again washed only. I suppose the acidic components in the crude RDX evaporate easily and allow washed only RDX to be quite stable.
Is it a myth that heavily NOx contaminated WFNA is unsutable for straight hexamine nitrolysis? The clear WFNA gives off NOx during the process anyway so why bother clearing the acid from NOx?
Here's the average Joe's possible plan:
Use whatever fuming nitric acid available. Well after the synth, carefully heat the batch to 50C, to purge the unstable non RDX nitration products(IIRC). Dry in warm dark place. Recrystallization is optional under certain conditions. I believe RDX is a great way to learn about high R.E. materials with not as much hazard as other materials. The only bothering RDX hazard compared to nitric esters and organic peroxides is it's annoying flammability.

caterpillar - 29-4-2014 at 12:12

use hexamine dinitrate instead of hexamine- in this case reaction is not very sensitive to NOx, presenting usually in conc. HNO3. I used yellow nitric acid and failed, trying to use hexamine. But reaction with hexamine dinitrate was successful.

Ral123 - 29-4-2014 at 13:31

I can't imagine that the hexamine will completely fail where the dinitrate will work. Was everything else the same? I'm more worried of forming unstable products that would rot the storage stability.

NeonPulse - 29-4-2014 at 17:30

i cant understand why anyone would want to use the straight hexamine route given to the fact that the yeilds are greater and the synthesis proceeds more smoothly with using the dinitrate. it does seem less picky about dissolved NOx in it. The acid i have used in the handful of times i have made it was a light yellow and i dont believe it had any influence on the end result. i would think that if you are going to go to the trouble of preparing RDX then the small amount of time and acid used to make the hexamine dinitrate is worth the extra effort IMO. Also if you do go to the effort in the first place, then why not take the extra time to recrystallize the product. but then i could say the same on the effort of purging the NOx from the acid....

caterpillar - 30-4-2014 at 05:11

Quote: Originally posted by Ral123

I can't imagine that the hexamine will completely fail where the dinitrate will work. Was everything else the same? I'm more worried of forming unstable products that would rot the storage stability.

I can. I made such experiments. One problem with hexamine is that reaction with nitric acid is exothermic (base + acid), but reaction of didnitrate is the mild one. According to russian book, written by Orlova, there is a special method for performing oxidization of unstable linear nitramines. One have to mix solution of RDX in nitric acid with simple water- drop by drop. This mixture will boil and produce NOx, but simultaneously all unstable nitramines will be destroyed (and BTW one will get large crystals of RDX). Final concentration of nitric acid must be something like 50% (or 60, i do not remember now). This diluted nitric acid later can be used to make hexamine dinitrate.

Ral123 - 30-4-2014 at 09:34

As I know RDX can be stored for 20 years. What stabilising additives do you think are appropriate? Urea would form water with the decomposition products. Sodium carbonate is quite a base. Magnesium bicarbonate, diphenilamine?

caterpillar - 30-4-2014 at 12:04

As I know, RDX can be stored for infinity and does not require stabilizing addictive at all. Do not worry about it- RDX is not NG.

simply RED - 30-4-2014 at 12:13

I have bought a "100% nitric acid" that was stored for tens of years in the "store". It was so impure that no RDX could be synthesized with it no matter with hexamine or HDN. Even after purging yield was low. But it was very good for nitrate esters...

Napolean Dynamite - 30-4-2014 at 12:57

I have a relative who does some blasting operations in mines and uses RDX left over from WW2 on occasion.

Ral123 - 30-4-2014 at 13:18

Quote: Originally posted by simply RED

I have bought a "100% nitric acid" that was stored for tens of years in the "store". It was so impure that no RDX could be synthesized with it no matter with hexamine or HDN. Even after purging yield was low. But it was very good for nitrate esters...

I've noticed quite nice yields from crude distilled NA/hexamine. Was your NA slightly yellow or dark red? I wonder if bubbling O2 or adding urea peroxide is a partial solution?
As for storing crystalline RDX, in my opinion it burns no slower then smokeless powder, and is no less flammable. Could it be that DDT in case of accident is a significant hazard. I've noticed the industry and military is staying away from crystalline material unless for basecharge/booster charges maybe.

simply RED - 30-4-2014 at 23:59

The NA was dark red with no chance to be completely purged. Yes, fresh distilled always gives good yields.

Manifest - 1-5-2014 at 13:47

Where the hell do you get Acetic Anhydride in the UK? Is it used in heroin production? Is that why it's so hard to come by?

VladimirLem - 1-5-2014 at 21:42

Quote: Originally posted by Manifest

Where the hell do you get Acetic Anhydride in the UK? Is it used in heroin production? Is that why it's so hard to come by?

yepp...its pretty hard to get it these days cause you can make diacetylmorphine with it....and many many interesting explosives too IF you had it...

Ral123 - 2-5-2014 at 02:28

I have a little of such acid http://en.wikipedia.org/wiki/File:Fuming_nitric_acid_40ml.jp...
I tried a little CO(NH2)2 and H2O2 30% and bubbling O2, but they didn't change it much. Both gave vigorous reaction. Do you think I have a chance if I heat it to 30-40C and try to suck the NOx with a 50ml syringe? May be a straw starting with azide, then ETN and finally RDX can show their performance in small diameters.

simply RED - 2-5-2014 at 06:29

I could not succeed purging very degraded acid. The answer is to use it fast after distilation.

Ral123 - 2-5-2014 at 11:59

I've had a super quick runaway when heating to 50C. It destroyed all the yield. The batch was only 30ml, I suspect there may have been unreacted material. My 300ml runaway took a lot of seconds after 30C to take off. In my second attempt(again 30ml WFNA/straight hexamine) I had about the volume of a well rounded tea spoon of fluffy material.

markx - 6-5-2014 at 00:14

I wonder...has anyone here succeeded in the E-method synthesis of RDX? I have found a couple of references on the net and also on this board, but it all seems very inconclusive. Mostly a failure is reported and the conditions are not very well described. The original patent text is also quite vague and of not much use if one tries to retrace the steps of original synthesis. I'm very facinated by this route of synthesis as it is (if it supposedly works..of which I am not so sure at all) the only method that does not require the presence of WFNA. Even if the yields would be low compared to other methods, I would still welcome the possibility to get by without WFNA....it's just a pain to distill. I have done it, but really the benefits do not outweigh the hassle. I find it is wasteful in amateur setups and there is no point in going pro on utilisation of the wastes....exponential growth in trouble

As a matter of fact I did perform a quick proof of concept experiment on the E method myself last year (small scale of course)....but I was sloppy and careless in preparation, lacking the proper equipment. Temperature was fluctuating...It was a total failure, but I have not given up yet.

The questions that plaque me are:

Is the presence of the catalyst of undeniable importance in initiating the reaction?

What is the correct temperature for performing the E method syntesis without the catalyst?

What kind of degree of polymerization is optimal for the paraform to be used ? There are different varieties out there and they do have different properties.

But as far as I have understood these questions have been asked before by so many....
Nevertheless, I would really appreciate it if anyone cares to share their knowledge or/and experiences on the subject.

caterpillar - 6-5-2014 at 13:35

Well, let's try to compare usual method (or K- method) with E-method. If you have not Ac2O in a hand reach, its preparation is a headache too. I suspect, that it is more problematic, than distillation of nitric acid. I know about some methods like distillation of dry mix- CH3COONa + Al2(SO4)3. But it is distillation too and requires higher temperature. And what about catalyst- BF3? Where do you plan to get it? But distillation of nitric acid is not as difficult, as you think. Steel does not react with concentrated HNO3 and you may use coffee pot instead of glass distillation apparatus. Use asbestos instead of gum corks. Nothing extra ordinal.

Motherload - 6-5-2014 at 21:39

I have access to AcAn. I have about 3 liters at the moment.
I however don't have any paraformaldehyde but lots of trioxane.
The only reason I haven't attempted the synth is because I live in a
densly populated area and don't know what kind of attention gathering
odors this method might produce aswell as if the trioxane can be substituted
for para.
Any input ?

markx - 6-5-2014 at 23:18

What isomer of trioxane are you in posession of? I trust the 1,3,5-trioxane might be a good candidate for its symmetry, but I have no evidence to back it up. It seems the E method is one of the least favored routes....I have not seen many references to it, apart from rather shallow descriptions in Urbanski and the original patent texts. Some older posts from forums and descriptions of attempts to apply the method circle the net, but their credibility is to be taken with a grain of salt. I guess in light of that fact there has to be a reason for it.
Actually the biggest problem that I saw when attempting the synthesis last year was the fact that neither paraformaldehyde nor ammonium nitrate were soluble in hot Ac2O to any noticeable degree. It might be a slow process that takes more time or requires a higher temperature or a different paraform with lesser polymerisation, but my heating failed and I could not keep the temp above 60C for more than 20min. But alas, during that time I saw no appreciable dissolving of the components.

Motherload - 7-5-2014 at 09:46

I have 1,3,5 trioxane used in military fuel tablets, which I purified by subliming it.
Megalomania's method required the temp to be around the 90*C mark if no catalyst is used. On the other hand ... I am tempted to use it with HNO3 and NH4NO3 and Hexamine for better yields, once I get around to distilling some HNO3..
Trying to figure out which method is more efficient and economical.
AcAn costs me about $55 a litre and can only buy a litre every couple of months without raising suspicion.

caterpillar - 7-5-2014 at 12:53

Perhaps, there is a better way to use Ac2O. You may try to prepare Solex or HMX. Read corresponding articles from dear Jared.

Motherload - 8-5-2014 at 00:22

Not as efficient use according to the patents. Besides I will generate some HMX in the E Method.
HMX synth requires a large surplus of WFNA and AcAn. Doesn't seem feesable .... Econo wise given the marginal better performance.

[Edited on 8-5-2014 by Motherload]

markx - 15-5-2014 at 10:01

Right....I pulled myself together and gave the E method a new try. I built a PID thermostating system and rigged up a water bath with it. Into the bath I placed a tall retort equipped with a thermometer and magnetic stirrer.
I measured 27ml of acetic anhydride into the retort, turned on the mixing and let it equilibriate at 90C. This took some overhead from the PID setpoint...about 2,7C to be exact (the PID setpoint @ 92,7C).
As the anhydride was heating up I weighed 10g of ammonium nitrate into one beaker and 3,6g paraform into another.
I added about 1/3 of the AN to the hot acetic anhydride and watched it crumble and dissolve partially...OK, good sign

I then proceeded to addin the paraform in small amounts...perhaps 40mg at a time. Immediately the temperature in the retort rose to 92C and a noticeable gas emission began in the liquid. Sucess!! I have a definite reaction! I proceeded with adding the paraform and AN in small increments, watching the temperature and keeping it in the limits of 88-92C. To accomplish that I added ice cubes to force the temperature down when it rose above 92C, the PID took over to bring it back up to 90C. As temperature fell below 88C the bubbling almost stopped and reaction seemed to grind to a halt. The whole process took 75minutes, accompanied by vigorous bubbling of the anhydride, some brownish gas emission as temp went above 92C and the gradual vanishing of solid precipitate of AN and paraform from the retort.
After having completed the addition of the components I kept the temperature at 90C and the stirring on. Bubbling stopped about 10-15min after having added the last of paraform and no solid preciptate is seen in the retort....the Ac2O is slightly milky though. Liquid seems to have a greenish tint. I turned off the heating and lifted the retort out of the water bath to let it cool down.
After about 10min it had cooled to around 60C and I crashed the contents into 500ml of ice cool water. Water turned opaque, but no immediate precipitate like when crashing the WFNA and RDX mixture from the straight nitrolysis.
After letting the whole cocktail sit for another 15 min I see a slow precipitaton of fluffy white solid....seems awful lean. Maybe a few mm thick layer on the bottom of the beaker. I'll just let it seddle for 24h and then proceed with filtering and further tests. At least a reaction and a result...yet inconclusive though

Turner - 15-5-2014 at 13:03

You should post the yield when it dries

markx - 15-5-2014 at 13:29

Quote: Originally posted by Turner

You should post the yield when it dries

The yield will unfortunately be absolutely dismal.....I can already tell by the eye. I will report the numbers tomorrow when it has dried.
Although I can confirm that the precipitate is RDX (at least the majority of it). I forced a small amount to dry at elevated temperature and did the burn test....characteristic hiss and flame. I compared it to the confirmed sample product from straight hexamine nitrolysis from last year...

As for the catalyst...perhaps one could use a less volatile analogue of BF3? Perhaps ZnCl2, AlCl3, TiCl4, SnCl4 could have a similar beneficial effect? Any comments and suggestions are welcome and valued.

I really would like to explore this synthesis route in more detail and practice...for some reason I find the E-method especially appealing.

[Edited on 15-5-2014 by markx]

markx - 15-5-2014 at 22:40

The numbers are in........dried yield without recristallisation was 0,7g.
This amounts to about 12% of the expected yield when calculated based on the numbers of Urbanski (which is already represented as a 65% yield compared to theoretical maximum).
Absolutely dismal, as I already stated....but now the concept is proven. It is possible to form RDX without the direct involvement of concentrated nitric acid. Time to begin with the development and introduction of improvements!

First of all I think that recristallisation of AN should be a starting point, as I used a fertilizer grade and it is not the purest one around.
Secondly the investigation of different synthesis temperatures could yield some insight on possible improvements in yield.
And as a third option the investigation of possible alternative catalysts from the lewis acid family.

As it happens I still have the connections to my former employers who engage in the field of carbide derived carbon synthesis. Chlorination of metal carbides at high temperatures that yields a residual carbon skeleton with very special properties and a huge amount of chlorides (most of which are strong lewis acids TiCl4, AlCl3, boron and molybdenum clorides too). So I should be in a sweet spot with regards to obtaining possible catalysts

Found a reference to another descrition of the E-method. In this one the use of BCl3 is noted...could be a mispelling or a reference to the possibility of using another catalyst.
Find the article attached:

[Edited on 16-5-2014 by markx]

Attachment: Conception for the investigation of contaminated munition plants.pdf (404kB)
This file has been downloaded 801 times

markx - 20-5-2014 at 23:18

I performed a second run of the E-method to get some illustrative material:

The improvised synthesis apparatus

The reagents (27ml Ac2O, 3g paraform, 16g dried AN)

Equilibriating to 80C and addition of AN

Equilibriating to 88C with small amount of paraform added. Start of reaction with the release of brown fume. Slow addition of paraform is continued. Vigorous gas evolution is observed in the solution and the reactor temperature is kept within 89-90C by the exotherm.

[Edited on 21-5-2014 by markx]

[Edited on 21-5-2014 by markx]

markx - 20-5-2014 at 23:58

Continuation of the process:

The reaction is finished with all of the AN and paraform consumed. The end of the reaction proceeded with extraordinary vigor by consuming about half of the solid AN still left in the reaction within a few minutes. The exotherm was not excessive though...a rise of only 1,5C to a maximum of 90,5C and then a sudden drop to 88C of the waterbath equilibrium.

Solution was left to cool and then crashed into 500ml cold water. The pictures show the resulting precipitate after about 7 hours .

Again the yield is low and judging by the eye it matches the result from first synthesis.

I tried to perform the synthesis on a lower temperature this time (80C), but it will not start under 88C without any catalyst. I'm starting to think that the lewis acid catalyst plays a key role in this synthesis and without it the yield will suffer greatly from the side reactions and or possibly the too high temperature of the reagent mixture.

Motherload - 21-5-2014 at 09:16

Your ratios seem off.
3 gm para and 16 gm NH4NO3 for 27 ml of AcAn.
Mega's method used around 10 gm para and around 12 gm NH4NO3 scaled down 10X iirc.
His page is down ... I'll look for a hard copy.
I have heard people on the board, disliking his methods, but can be used as a guide.

markx - 21-5-2014 at 09:52

Quote: Originally posted by Motherload

Your ratios seem off.
3 gm para and 16 gm NH4NO3 for 27 ml of AcAn.
Mega's method used around 10 gm para and around 12 gm NH4NO3 scaled down 10X iirc.
His page is down ... I'll look for a hard copy.
I have heard people on the board, disliking his methods, but can be used as a guide.

In the first synthesis I used the ratio 3,6/10g para/AN based on an old post from parazite forum (could be total rubbish)....in the seconf one I used the ratio given in the original Ross Schiessler patent and that was stated as 3/16g. Anyways the result was just about the same with both ratios.
Of course any suggestions on how to improve the situation are welcome

markx - 21-5-2014 at 13:19

I just finished drying the yield from the second synthesis and as a matter of fact it was only 0,35g......so just about exactly 50% less than the first result. The difference was in the ratios of parform/AN. It seems that the original patent ratio works much worse on my particular set of raws than the 3,6/10g ratio that I used in the first synthesis. Some food for the thought...

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