Dany
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The ugly sister of nitroglycerin
An explosive compound is a materials capable of releasing huge amount of energy in a short time (in the order of microseconds). Condensed explosive
(solid or liquid) are by far the most studied materials owing to their high density (~2g/cm3) and detonation performance (Dcj
~9-10 km/s and Pcj~45-50 GPa). Since the synthesis of Nitroglycerin (NG) in 1848 many investigators tried to synthesis more and more
powerful explosive. One compound that is similar to NG is 1,2,3-Trinitraminopropane or the nitramine analogue of NG (hence the name ugly sister of
NG). 1,2,3-Trinitraminopropane was first described by Blomquist A.T. & Fiedorek F.T [1] in 1944. however no one investigated in depth this
compound until 2009 were Klapotke et al. [2] & Shreeve et al. [3] published two independently papers on the synthesis and
characterization of 1,2,3-Trinitraminopropane along with other interesting explosive. here i'll focus on the synthesis and detonation properties of
1,2,3-Trinitraminopropane only. Although the synthesis of NG is straightforward (nitration of glycerol with mixed acid
HNO3/H2SO4 [4]) the synthesis of 1,2,3-Trinitraminopropane is not. 5 steps are needed to get
1,2,3-Trinitraminopropane. First 1,2,3-triazidopropane is reduced to 1,2,3-triaaminopropane using triphenylphosphine. Next, the amino group are
protected using ethyl chloroformate to form a urethane (remember primary amine cannot form nitramine because they undergoes decomposition when mixed
with concentrated nitric acid, indeed few exceptional examples exist, for more detail see [5]). the third step is the nitration of the urethane using
HNO3/(CF3CO)2O. Now (forth step) come the deprotection of the nitrogen (removing the urethane protecting group) using
ammonia which in the same time form the ammonium salts of the nitramine. The final step is the protonation of the ammonium salt to regenerate the
nitramine. The detailed synthesis can be found in [2].
The two references [2,3] shows some discrepancies regarding the physical/chemical properties of 1,2,3-Trinitraminopropane. The reported crystal
density in [2] is 1.783 g/cm3 vs 1.753 g/cm3 in [3]. also large deviation in calculated heat of formation (HOF) exist between
the two studies HOF= -161 kj/mol [2] vs +324 kj/mol [3] which can be attributed to the different quantum chemical method used in the two papers. An in
interesting feature of the new trinitramino is the reduced impact sensitivity when compared to NG (7 Joule vs 0.2 Joule for NG) which according to [2]
is due to the hydrogen bonding present in the trinitramino which also increase density relative to NG. below are important properties of
1,2,3-Trinitraminopropane:
Dcj= 8598 m/s [2] vs Dcj= 8933 m/s [3].
Pcj= 307 kbar [2] vs Pcj= 356 kbar [3].
OB(%)= -28.6
Tdecomposition= 134°C (using DSC with 5K/min heating rate)
So by replacing the nitrato groups in NG by nitramino groups you increase density from 1.591 g/cm3 for NG [2] to 1.753-1.783
g/cm3. Also Dcj and Pcj for the trinitramino are higher than that of NG ( Dcj=841-1176 m/s and
Pcj= 71-120 kbar higher for the trinitramino). So with these fact the 1,2,3-Trinitraminopropane deserve the nickname: the ugly sister of
NG. below you will find references used for writing this thread along with attached paper of [2] and [3].
References:
[1] Blomquist, A.T., Fiedorek F.T, OSRD 4134, 1944, 2, 99-101.
[2] Thomas ALTENBURG, Thomas M. KLAPÖTKE, and Alexander PENGER, CEJEM, 255-275, 6(3-4), 2009.
[3] Young-Hyuk Joo and Jean’ne M. Shreeve, Chem. Commun., 142–144, 46, 2010.
[4] Jacqueline Akhavan, The chemistry of explosives, 2nd edition, 2004.
[5] Tadeusz Urbanski, chemistry and technology of explosives, vol. III, 1967.
Dany.
Attachment: [2].zip (1.8MB)
This file has been downloaded 548 times
Attachment: [3].pdf (558kB)
This file has been downloaded 872 times
[Edited on 1-10-2013 by Dany]
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franklyn
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Certain Aliphatic Nitramines & Related Compounds (1944)
www.dtic.mil/dtic/tr/fulltext/u2/a801458.pdf
Curious that Ethylene Dinitramine offers no improvement on Nitroglycol.
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Melmoth
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Reference:
[4] Jacqueline Akhavan, The chemistry of explosives, 2nd edition, 2004.
http://www.e-reading.biz/bookreader.php/141462/The_chemistry...
"This species has amused itself to death"
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papaya
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Have anybody seen the nitramine brother of PETN?
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DubaiAmateurRocketry
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Dany your posts are often interesting and entertaining, thank you for sharing.
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Dany
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Quote: Originally posted by franklyn  | Certain Aliphatic Nitramines & Related Compounds (1944)
www.dtic.mil/dtic/tr/fulltext/u2/a801458.pdf
Curious that Ethylene Dinitramine offers no improvement on Nitroglycol.
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Well franklyn there are several improvement. First the density, Ethylene Dinitramine (EDNA) =1.77 g/cm3 [1] vs Ethylene glycol dinitrate
(EGDN)= 1.49g/cm3 [2], this is a critical factor for weapons were size is the limiting factor, so with higher density you can pack more
explosive in a given volume.
from [1] i copied this paragraph on the propertie of EDNA or haleite:
"From the 1920's onward, scientists at Picatinny Arsenal had been trying to find a compound that would have the high brisance of RDX without the
sensitivity to friction and impact. Research on this problem, principally by Dr.George C. Hale, chief chemist, led to the discovery of
ethylenedinitramine (EDNA or haleite) the first entirely American high explosive. More powerful than TNT, EDNA was slightly less powerful
then RDX but was also less sensitive"
so EDNA is also relatively insensitive vs sensitive nitrate ester EGDN (for the same reason that 1,2,3-trinitraminopropane is less sensitive than
nitroglycerine).
Also from [1] a unique propertie for EDNA over all known explosive not just EGDN:
Haleite (EDNA) is an explosive that combines the properties of a high explosive like TNT and an initiating agent like mercury fulminate or lead
azide, possessing a high brisance and comparatively low sensitivity. No other high explosive is known which has such a low sensitivity to impact
and at the same time so readily explodes by heat
finally, the detonation velocity of EDNA @ 1.55 g/cm3 is 7883 m/s [1]. In [3] the calculated Dcj & Pcj of EDNA @
1.71 g/cm3 using the Becker-Kistiakowsky-Wilson Equation of State (BKW EOS) is Dcj= 8534 m/s & Pcj= 310 kbar
while the experimental [2] Dcj of EGDN @ 1.49 g/cm3 is Dcj= 7356 m/s. assuming that the explosion product of EGDN is
a polytropic gas we use the formula Pcj=ρD2/4 to calculate the Pcj so we get Pcj= 202 kbar. As we can
see EDNA has superior detonation performance compared to EGDN.
References:
[1] TM 9-1300-214, Military explosives.
[2] G. D. Kozak , Measurement and Calculation of the Ideal Detonation Velocity for Liquid Nitrocompounds, Combust., Explos. Shock Waves,
34(5), 581-586, 1998.
[3] Charles L. Mader, Numerical Modeling of Explosives and Propellants, Third Edition, 2008.
Dany.
[Edited on 5-10-2013 by Dany]
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Dany
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An alternative for EGDN is EDNA or haleite:
a comparison between EGDN and EDNA can be found in this thread:
http://www.sciencemadness.org/talk/viewthread.php?tid=26459&...
Dany.
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