Sciencemadness Discussion Board

Isopropyl nitrate

Zinc - 15-9-2010 at 12:35

I could only find a small amount of information about this explosive, but it caught my attention.

Its det. velocity is 5100 m/s, and is quite unsensitive. I have read a long time ago on some webpage (couldnt find it anymore) that it can be made by nitrating a solution of urea (dont know how concentrated) in isopropanol with azeotropic nitric acid, and that the synthesis is easy to perform.

The chemicals are relativley easy to obtain, and if the synthesis really is easy it would be a nice explosive to try :)

So did anyone here try to make it, or has some information about it?

Anders2 - 15-9-2010 at 14:02

A less than reliable source stated the detonation velocity as approximately 5400 m/s
but I can not confirm this. It is very insensitive, despite being a nitrate ester.

It is used as rocket fuel on some racing cars, known as "Thermolene".
Isopropyl nitrate is still used as the liquid fuel component on some rockets in Azerbaijan, to reduce the quantity of oxidizer required.

One thought would be to first make Isopropyl Nitrite, which only requires concentrated HCl solution. http://www.shadowrx.com/forums/showthread.php?t=933

Then dessicate out all traces of water, and bubble in dry nitrogen dioxide.
This might turn the nitrite (which is vulnerable to being oxidized) to the nitrate ester.

NO2 will oxidize a nitroso group to a nitro, so the above has a chance of working, which could potentially avoid the use of concentrated H2SO4 for the synthesis.



the Z man - 15-9-2010 at 16:13

Found on an old E&W thread:
"Take 5 ml of 50%-65% nitric acid, add about 100 mg Urea, cool with cold water bath and add 5 ml IPA, NOT LESS!!! [Using the stoichiometric best amount of IPA, here about 2,5 ml, may cause too much heat generating and decomposion of the mixture.] When you cool the solution you prepared after 1-2 hours a IPN-Phase on the acidic solution should have formed."
From the thread seems that the reaction is a little weird sometimes going runway sometimes not forming IPN at all.
I have tried some time ago using calculated amounts of H2SO4 and ammonium nitrate (to archieve the right concentration) instead of the HNO3 and not getting anything if the temp was too low but getting somekind of runway with vigorous boiling (but not much warming) if the temp was a little higher. Also in the runway gave off no coloured NOX but instead a colourless, sweetish smelling gas/vapour that gave me dizziness. It reminded me Isopropyl NITRITE very much. At the end of the runway I actually found a yellow layer on top of the mixture but it still looked like the nitrite ester (smell and dizziness) and it dissolved (?!) in water/salt solution.
Indeed a weird reaction.

AndersHoveland - 14-2-2012 at 03:23

Quote:

Isopropyl nitrate boils at 101-102°. It is easily inflammable, burning with a white lumious flame, and its superheated vapor explodes violently when ignited. Direct nitration of isopropyl alcohol is difficult due to oxidation of the carbon atom carrying the secondary hydroxyl group.

Direct nitration was found to yield mainly acetone due to the oxidation of the secondary alcoholic group. However a process for the continuous nitration of isopropyl alcohol in the presence of urea has been described in Imperial Chemical Industries patents (W.G.Allen and T.J. Tobin -British Patent 696489-1953;749734,749844-1956

iso-propyl alcohol and urea were introduced into nitric acid (over 40 % HNO3) at its boiling temperature
and a current of air stirred and removed unstable products.
According to Desseige (G.Desseigne, Mém.podres 37,97;1955) the method gave ca. 80% yield. He used nitric acid of over 50 % HNO3 at 108-110 C.


Quote:

Take 5 ml of 50%-65% nitric acid, add about 100 mg Urea, cool and add 5 ml isopropanol, NOT LESS!!! [Using the stoichiometric best amount of isopropanol, here about 2,5 ml, may cause too much heat generating and decomposion of the mixture.] When you cool the solution you prepared after 1-2 hours a isopropyl nitrate-Phase on the acidic solution should have formed.

put about 5 ml HNO3 55% in a test tube, then add urea until you find that it's enough.....you have to find out yourself....then add about 5 ml isopropyl alcohol and then let the test tube swim in cold water....at first the urea bubbles, ´reacting with the HNO3, and then, after a while, a thick layer of IPN forms on the acid mix.


Preparation of Isopropyl Nitrite

A mixture of 45 ml concentrated sulfuric acid, 30 ml water and 110 ml isopropyl alcohol, previously cooled to 0 centigrades, was added to an ice cold solution of 114 grams of sodium nitrite (My edit: I assume they mean nitrate here, not nitrite. What they are calling isopropyl nitrite in this text has the formula of C3H7ONO2, they use it in the next step to make sodium azide. I've normally seen this called isopropyl nitrate though.) in 450 ml of H2O. Slow addition required about two hours in order to maintain a temperature around 0 centigrades. The upper oily layer was separated and washed three times with 30 ml portions of 5 gram 100 ml sodium bicarbonate solution and 22 grams NaCl 100 ml solution respectively.


Apparently the reaction can be very violent is not done properly.


some caution might be a good idea:
Quote:

The nitration of isopropanol using fuming nitric acid and sulphuric acid yielded nitroform


Quote: Originally posted by Anders2  
, and bubble in dry nitrogen dioxide.
This might turn the nitrite (which is vulnerable to being oxidized) to the nitrate ester.

NO2 will oxidize a nitroso group to a nitro, so the above has a chance of working


I do not think this would work. Nitroso groups are different than nitrite esters.

[Edited on 14-2-2012 by AndersHoveland]