Sciencemadness Discussion Board

More usefull explosives when making RDX

underground - 18-10-2013 at 00:00

As i saw from Wikipedia, When you are trying to make some RDX from WFNA, dinitromethane and ammonium nitrate are produced also, but i have never saw anyone who when he made RDX, collect any of them.


From Wikipedia:

"It is obtained by reacting white fuming nitric acid (WFNA) with hexamine, producing dinitromethane and ammonium nitrate as byproducts.[9]

Hexamine + 10 nitric acid → RDX + dinitromethane + ammonium nitrate + 3 water
(CH2)6N4 + 10HNO3 → (CH2-N-NO2)3 + 3CH2(NO2)2 + NH4NO3 + 3H2O"

[Edited on 18-10-2013 by underground]

DubaiAmateurRocketry - 18-10-2013 at 01:04

It is sad how the RDX yield is so low.

I guess Dinitromethane is sensitive, probabaly around EGDN or NG

Dany - 18-10-2013 at 01:28

Well, first there is an error in the side product cited in wikipedia (as usual, since people who wright these article are often non-expert in these domain). Fortunately, they cited the original paper [1] who mentionned the side products. The side product is not dinitromethane but methylene dinitrate and ammonium nitrate. Another important study [2] on the side products formed during nitrolysis of hexamine mention the formation of seven compounds as side products or as intermediate. These compounds are detected and analyzed using the 1H and 13C NMR spectroscopy. Now, why nobody collect them depend on many factors. Maybe the yield is very low and the recuperation is very tedious and hazardous. there is now economical nor military interest in these highly sensitive explosive. If somebody is interested in these side product (e.g., for academic research) he can find (or invente) a suitable, safe synthesis that yield these product in good quantity.

References

[1] Luo, K.-M., Lin, S.-H., Chang, J.-G., Huang, T.-H., "Evaluations of kinetic parameters and critical runaway conditions in the reaction system of hexamine-nitric acid to produce RDX in a non-isothermal batch reactor",Journal of Loss Prevention in the Process Industries, 15 (2),119–127, 2002.

[2] Fang, Zhi Jie; Chen, Ju; Li, Fu Ping, Study on the nitrolysis of hexamethylenetetramine by NMR spectrometry. Part 3. The NMR spectral data of some products and intermediates from the nitrolysis of HA, Propellants Explos. Pyrotech. , 22, 314-316, 1997.

Dany.

[Edited on 18-10-2013 by Dany]

caterpillar - 18-10-2013 at 04:31

Read this: Organic Chemistry of Explosives by
Dr. Jai Prakash Agrawal and Dr. Robert Dale Hodgson . There is some valuable info. Nitrolisys of hexamine produces the whole bouquet of unstable linear nitramines. if you dislike that this synthesis requires lot of nitric acid, there are three ways to save this valuable compound. You may use hexamine dinitrate instead of pure hexamine, you may regenerate nitric acid, extractind it with CH2Cl2 and you may try use mixed acid (or even some nitrate plus sulfur acid). it is well known, that sulfur acid destroys RDX, but Anders Hoveland gave me the link to one interesting method. "SynthesisofKetoRDʍ 36; anditsCharacterizaᦈ 4;ionsCalculation
ArashShokrollahi , AbbasZali , HamidRezaPouretedaᦇ 6; , MohammadHosseinKesᦇ 2;avarz

CHINESEJOURNALOFENᦃ 7;RGETICMATERIAL

Vol.16 , No.1
February , 2008

(Sorry for unicode) This mehods lets one to make mixture of RDX and Keto-RDX, using mixed acid.

Dany - 18-10-2013 at 04:51

I like the synthesis of RDX that begin with the R-salt (1,3,5-trinitroso-1,3,5-triazacyclohexane). Unlike the Bachmann process, the RDX obtained by this method is free of HMX and is very pure. The attachement include the synthesis of the R-salt and two method for pure RDX synthesis performed at Lawrence Livermore National Laboratory (LLNL).

Dany.

Attachment: Synthesis of pure RDX.pdf (207kB)
This file has been downloaded 707 times


Ral123 - 18-10-2013 at 06:03

Waste a ton of N2O5 enriched HNO3 and a some other exotic precursors to obtain special HMX free RDX :D
Is there a way to help shift equilibrium to more HMX content from HDN/HNO3 method? I had a runaway batch once, but the product didn't burn differently from normal. IIRC there isn't a convenient way to make HMX without acetic anhydride. If I make HMX, there will be HMX video on YT...

caterpillar - 18-10-2013 at 11:23

The only problem with R-salt is that this compound is carcinogenic. According to Organic Chemistry of Explosives, conversion of R-salt to RDX goes better with the aid of concentrated HNO3 + H2O2- method, using N2O5, dissolved in HNO3, gives lower yield. BTW, once I made R-salt salt and mixed it with AN. After few days violent reaction occurred.

caterpillar - 18-10-2013 at 11:30

There is a way to make HMX without acetic anhydride- nitrolysis of DPT

hungryman - 18-10-2013 at 12:21

why avoiding using acetic anhydride in HMX synthesis?? it is cheap and relatively safe

Metacelsus - 18-10-2013 at 16:13

It's also unobtainium for amateurs, as it can be used to acetylate morphine to make heroin, and is thus tightly controlled.

golfpro - 18-10-2013 at 17:07

It can be synthesized, anything can be if you want it bad enough and are willing to put in the time and effort. You have to acquire some other reagents and appuratus' just to make the reagents for making the acetic anhydride I think. I decided it's not worth all the time at the moment.

How loud is 18g of plasticized (high density) RDX in comparison to 5g lightly pressed ETN? I am going to make a video of this plastique on a steel frying pan, I was about to do it but I decided it would probably be very loud and cars would stop and whatnot: bad, but my only place to go is in the mountains only a few hundred ft. off of the road






testimento - 2-1-2014 at 19:56

Is it possible to recover this methylene dinitrate chemically because it forms so large portion of the reactants? Could one use some reaction to regain the nitrates it contain?