MrRedox602
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Maximization of a high-denisty ETN-based HE
Hello, All.
I have a general question for those out there experienced enough to provide a thorough response.
Which option (in your educated opinion) would provide the best combination of:
a) Safety and ease of manufacture
b) High VoD
c) Density
d) OB
Here are your choices:
a) Cast ETN/Al
b) PIB or polystyrene butadiene based binder
c) ETN/NM
d) ETN/NG
e) ETN/EGDN
f) ETN/mineral oil
After a very, very long period of extensive research, I can't draw the line and decide. Can you help?
Note: This is somewhat of a repeat post due to the fact that the "Unconventional Shaped Charge" thread has not had any activity on it for a long
while. I figure I'd get much more expedient replies here. I hold an enormous amount of respect for the experienced members on this awesome forum after
doing a great deal of research here. I hope to see a nice discussion on this topic.
Thank you in advance.
"Any problem on Earth can be solved with the careful application of high explosives. The trick is not to be around when they go off." -Valkyrie
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DougTheMapper
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IMO:
1: Cast ETN/Al: I would really reccommend against trying this unless someone else has done it. I believe another user discovered that
ETN could be made fuse-sensitive by keeping it in intimate contact with Al. (Lord Emrone I think was his name) Attempting to heat a mixture of the two
in an attempt to cast them may cause an explosion. Due to the slight positive oxygen balance of ETN, the addition of stoich. Al will make for a
marginal performance increase at best. Al is best used with extremely oxygen positive explosives like ammonium nitrate.
2: PiB or PS/PiB: Not the best unless you're looking for something hard or something plastic. VOD will suffer because of the addition
of an inert ingredient. Also, to achieve the binding effects usually desired with these mixes, the oxygen balance will typically end up very negative
since ETN has only a slightly positive OB. Density will also suffer and thus brisance.
3: ETN/NM: A viable approach. NM has a significantly lower det. vel. than ETN but is oxygen negative and can help balance things out.
Density will surely increase as liquids will tend to fill air gaps in pressed ETN. ETN is likely soluble in NM, so watch out - this may just make a
syrupy paste at stoicheometric quantities.
4: ETN/NG: A very good choice. Not as cheap as using NM off-the-shelf, but NG has a much higher det. velocity of 7700m/s (compared to
6400m/s for NM). ETN is soluble in NG. Unfortunately, NG also has a slightly positive OB so it's not ideal and will not end up balanced. As with NM,
density will increase because of the addition of a liquid. There really are no rules about this composition since OB is not a factor in determining
the ENT/NG ratio, so anything between damp ETN and a liquid syrup can be obtained. Use care when mixing.
5: ETN/EGDN: Another excellent choice. It's less dense than NG but has a perfect OB and (some say) a marginally higher det. velocity.
EGDN is more volatile than NG and is subject to evaporation. Again, the entire mix will be slightly oxygen positive no matter what proportions are
used, so this will range from a damp powder to a syrup depending on the ratios used. "Power" may be slightly lower than NG/ETN because of slight
decrease in density, but 1,2-ethanediol is much cheaper than glycerol where I live.
6: ETN/mineral oil: The amount needed to bring the ETN to perfect OB will probably make a wet powder. As always, adding an inert
ingredient will lower det. velocity overall. Density of mineral oil is ~0.8g/cc so density will certainly suffer compared to cast ETN. However, lack
of airspace may actually have a slight increase in density over packed/lightly pressed ETN. I have never tried this.
Bottom line: Go with ETN/NG or ETN/EGDN, but be careful as both of these are absorbed through the skin and pose an inhalation hazard.
Watch out for the freezing point of the NG mix. EGDN was added to commercial NG to prevent freezing since freezing NG sensitizes it. I'm not sure if
the mixture will actually freeze near room temp, so it may just be fairly sensitive no matter what. It's not a peroxide, but exercise caution
nonetheless. As far as ease-of-synthesis goes, if you can make ETN, you can make NG or EGDN. The process is essentially identical, except with a
liquid extraction instead of a filtration/recrystallization.
I noticed you do not have any ETN mixes with oxygen negative explosives other than NM. You might try O-negative PGDN with O-positive ETN in oxygen
balanced ratios.
You might also try a trio of ingredients. Oxygen-positive NG/ETN might do really well with enough Al to balance it out. Get a 1/8" steel sheet and do
some 5g tests. We all surely want to see it!
-DTM
Victor Grignard is a methylated spirit.
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MrRedox602
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Thank you for the prompt and informative response!
1: Cast ETN/Al: I'm honestly kinda fearful of this process. I've read up on other users' experiences with casting Al-doped ETN, and some have reported
that the mix sometimes spontaneously detonated. Some reported that it happened just before it boiled (big surprise there, right?) and some reported
that it detonated shortly after melting. A reasonable explanation that I found is that the Al flakes 'create local hot spots' in the molten ETN where
the compound is more likely to decompose spontaneously. Still not quite sure, however.
2: PiB or PS/PiB: Great points.
3: ETN/NM: What are your thoughts on using a mixture of NM/Al to both preserve the thick consistency and OB the ETN?
4, 5, 6: You covered everything that I wanted to know. Excellent.
Hmmm...PGDN...great recommendation. Didn't think of that one  You've got my mind
going though. RFNA can easily be distilled and purified into WFNA. This can then be used to synthesize the ETN more efficiently than the nitrate salt
method AND (more importantly) prepare other OB negative HE's like RDX, HMX and TNT. A few of these binary mixes can be cast, right? How exciting!
"Any problem on Earth can be solved with the careful application of high explosives. The trick is not to be around when they go off." -Valkyrie
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Pulverulescent
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| Quote: | | EGDN was added to commercial NG to prevent freezing since freezing NG sensitizes it. |
Jeez! I can't believe that old misconception is still around!
Frozen nitro is quite difficult to initiate ─ the hazards of remelting nitro did, though, lead to many unfortunate accidents!
P
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MrRedox602
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Quote: Originally posted by Pulverulescent  | | Quote: | | EGDN was added to commercial NG to prevent freezing since freezing NG sensitizes it. |
Jeez! I can't believe that old misconception is still around!
Frozen nitro is quite difficult to initiate ─ the hazards of remelting nitro did, though, lead to many unfortunate accidents!
P |
Interesting information. So what's your take on the situation, Pulverulescent?
"Any problem on Earth can be solved with the careful application of high explosives. The trick is not to be around when they go off." -Valkyrie
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DougTheMapper
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Aha! I found this google book describing NG to actually be less sensitive than liquid NG, but then goes on to talk about crystal stress and the fact that it
was people thawing NG with improper heat sources which caused most the trouble. I did not know that!
I believe you can use RFNA directly for the synthesis of ETN. However, my experience has shown that using less concentrated nitric acid is easier
because the nitration bath doesn't thicken up as much. I have used KNO3 before to make ETN and the end result was a paste of K2SO4 and ETN!
My 68% HNO3 with lots of 93% H2SO4 does the trick just nicely and the end product is still thin enough to be magnetically stirred. I don't have my
yields based on erythritol offhand, but they must have been OK because I repeated it many times. (This was years ago) Of course, using less
concentrated nitric means more sulfuric, and more cost. But sulfuric is cheap for me at around $16 USD/half gallon.
Yes, WFNA (and possibly RFNA) can be used to synth higher-end energetics. I remember my first WFNA. 
I'm not sure about HMX, but I know that TNT and RDX were used together in melt-cast fillers for fragmentation grenades. ETN is expected to be soluble
in these mixtures but will contribute to increased overall sensitivity (owing to the fact that RDX and TNT are initially insensitive)
As for the ETN/NM/Al, I'm not sure that the amount of Al required will even change the consistency. It's pretty small. Remember that 1 mol ETN has .5
mol extra O2, and 1 mol Al needs 1.5 mol O2. That means for every 2 mol of ETN alone you'd need to add 3 mol Al. That's 604g ETN per 81g Al, and Al is
nearly twice as dense. Adding NM (which is O-negative like Al) only decreases the need for Al overall. You can do the math to compare the heat of
formation of the products of ETN/Al and ETN/NM and see which is more energetic. Be aware, however, that adding Al yields Al2O3 on decomposition - a
solid. The NM may end up less energetic but may evolve more gaseous products and could be more "powerful."
Welcome to the horrible world of explosive prediction!
-DTM
Victor Grignard is a methylated spirit.
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Pulverulescent
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| Quote: | | Interesting information. So what's your take on the situation, Pulverulescent? |
I'd go with nitroglycol; (but check the lit. before trying it) easily and safely prepared, neutral OB and it can be satisfactorily gelatinised by a
couple of % of high-nitrogen NC at RT!
Nitroglycol headache, though, is something fucking else!!!
Its relatively low density, BTW, is more than made up for by its high heat of explosion . . .
P
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MrRedox602
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DTN, thank you for the heads up on the ETN synth. What ratios did you use in the strong acid mix? Also, I'll research more into binary HE mixes and
their separate, respective, characteristics. You've made some great points on the stoich analysis. The required mass of Al for OB would be pretty
small. What's this about the 'horrible' world of explosive prediction? I'm really enjoying all of this Weird, right?
P, great suggestion. Upon researching the compound and its properties/synthesis, I'm kind of hesitant about its sensitivity - especially when it
hasn't been washed and neutralized. I had the same fear with TATP, but after making it, handling it and storing it for short periods of time (with a
great deal of care involved in all of that), I got over that fear. Do you think it'll turn out to be the same situation?
Let's kind of focus in on something, here. Say that this ETN mix was being used for a shaped charge. Do you think that a simple OB (powdered) ETN/Al
mix do just as great of a job as a ETN/(NG, TNT, RDX, etc...)? I guess what I'm getting at here is this - is there really such a thing as overkill in
this scenario? Would I even need to worry about making other HE's or plasticizing it in the first place?
"Any problem on Earth can be solved with the careful application of high explosives. The trick is not to be around when they go off." -Valkyrie
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Pulverulescent
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| Quote: | | P, great suggestion. Upon researching the compound and its properties/synthesis, I'm kind of hesitant about its sensitivity - especially when it
hasn't been washed and neutralized. I had the same fear with TATP, but after making it, handling it and storing it for short periods of time (with a
great deal of care involved in all of that), I got over that fear. Do you think it'll turn out to be the same situation? |
I well remember the first time I prepared a few gms of HMTD!
I smoked a few joints that night and got so fucking paranoid over the little bit of powder that I could barely function!
I last made HMTD about three years ago - most of it is still sitting in my, ahem, lab, under water . . .
But nitroglycol is in a whole different league to peroxides as far as sensitivity is concerned!
Davis has a short, informative piece on it in "COPAE", available for download from the site-library.
P
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VladimirLem
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| Quote: Originally posted by MrRedox602 |
Let's kind of focus in on something, here. Say that this ETN mix was being used for a shaped charge. Do you think that a simple OB (powdered) ETN/Al
mix do just as great of a job as a ETN/(NG, TNT, RDX, etc...)? I guess what I'm getting at here is this - is there really such a thing as overkill in
this scenario? Would I even need to worry about making other HE's or plasticizing it in the first place? |
Hi
Sure, ETN/AL will be a strong compound BUT i dont get it: Why mixing with AL?
AL is extremly negative Oxigen...(~ -100%)
ETN around +5%
And, in most cases AL isnt really good for shaped charges (dunno why, just heard about that) - so, if your compound havent too many oxygen (like ANNM
75/25), AL doesnt make sense...i think...
Then, without a plasticiser or other stuff like vaseline/oil or using it as a cast, it will be difficlt to compress...
if you havent NG/EGDN, go for 93ETN/7vaseline or oil...
should be slight positive OB and you will get a good density compound with over 7000m/s and a lot of power
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DougTheMapper
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I use a 40:20:10 ratio of Sulfuric, Nitric, and Erythritol respectively by weight. This value is for the pure substances - if you want to use 93%
sulfuric and 68% nitric, you end up with those values divided by their corresponding percents. The aforementioned scenario results in a 43:29:10
ratio. If I remember correctly, yield was about twice the weight of erythritol put in.
If you've handled TATP, you will be very surprised at how hard ETN is to actually set off. It is worlds apart from TATP.
As for the shaped charge, you want maximum VOD and maximum density. Casting the ETN directly into the charge will work very well. I would guess that
blending with EGDN, PGDN, or NG and packing would be a close second, followed by packing dry powder as a last resort.
A note about OB - Consider the gains presented by balancing the oxygen of ETN. At only +5.3%, there isn't much more to be gained by the hassle. Adding
only a couple percent of any liquid to a solid is usually quite challenging to achieve a good blend. Imagine mixing a tablespoon of water with a cup
of flour... it will take some intense and prolonged kneading to achieve an efficient mix. Who wants to do that with a high explosive?
On that note, I have seen oil-based plasticizers and other liquid energetics efficiently mixed using a low-boiling solvent. Something like methanol
could be used to fully dissolve the ETN. The predetermined weight of NG, PGDN, oil, or whatever is then poured into the liquid and stirred until
homogeneous. The methanol is then allowed to evaporate, leaving behind sticky crystals of ETN coated evenly with the liquid. This is how most folks
get their PiB mixed with PETN, although they use gasoline to do it because it's cheap.
But really, I don't think the performance gain is worth it. Just melt your ETN on a water bath and pour it into the charge. The addition of 1% urea
supposedly helps to stabilize the ETN. Modelling clay can help seal the charge during casting.
-DTM
Victor Grignard is a methylated spirit.
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MrRedox602
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Well, it's decided. Sounds like casting the recrystallized and stabilized ETN is the most sensible thing to do for the project.
BTW, does anyone have experience initiating RDX with ETN, ETN/Al or TATP? If so, how'd you do it? I don't have the reagents or time yet to experiment
with this. Research hasn't proven terribly helpful yet. Seems like silver azide is the most efficient way of initiating it in full det, but that won't
be on the menu of concoctions.
"Any problem on Earth can be solved with the careful application of high explosives. The trick is not to be around when they go off." -Valkyrie
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VladimirLem
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edit
[Edited on 12-1-2012 by VladimirLem]
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Pulverulescent
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| Quote: | | Seems like silver azide is the most efficient way of initiating it. |
MF is cheaper, waaay more easily prepared, doesn't have the crystal-size-sensitivity the azides have and fulminate caps were the staple until fairly
recently . . .
P
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quicksilver
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I am politely asking the SPOON-FEEDING to STOP!
Everyone should at minimum should have read Davis completely prior to asking questions and those should be directed at energetic CHEMISTRY - NOT
practical applications.
ALL those questions are in Davis's book free for the downloading on this site.
The questions and dialog are the biggest "stop sign" I have seen for awhile. Before doing anything please check this out.
http://www.sciencemadness.org/talk/viewthread.php?tid=16612
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AndersHoveland
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want to add some (speculative) thoughts-
perhaps mix the EDN with a small quantity (10-20%) of dinitrotoluene. Dinitrotoluene (70°C) has a similar melting point to EDN (61°C), and unlike
with nitromethane, there would be no danger that the nitromethane would evaporate out. If however one is concerned that the small addition of
dinitrotoluene might raise the melting point a few degrees above 61, then a small portion (5-7%) nitromethane could be added to compensate for this.
For safety, it is ideal to keep the melting point as low as possible. Likely the addition of dinitrotoluene might not even raise the melting point,
rather forming a eutectic mixture instead. (remember, ETN should only ever be melted in a container inside a water bath, not in contact with the
bottom of the water bath).
Melted EDN, or EDN dissolved in a solvent (such as acetone or MEK) can also be absorbed into partially nitrated cellulose (cotton) for decreased
sensitivity. Excess nitrated cellulose should be used completely absorb the EDN, for example in a 6 to 4 ratio by weight. The solvent idea might be
less safe because the evaporation of the solvent could leave behind sensitive crystals of the EDN, whereas solidification of melted EDN leaves behind
a more amorphous solid fusion.
The two compositions described above could also be combined, EDN with some dinitrotoluene and absorbed into nitrated cellulose.
EDN would also likely form a less sensitive gel if absorbed into a mixture of polyethylene glycol and polyvinylalcohol. The solubility of
nitroglycerin in ethanol, for example, is reportedly 1 part nitroglycerin to 3.2 parts by weight ethanol, so the absorbtion into polyvinylalcohol
should be similar. The polyvinylalcohol itself, or course, could be partially nitrated, and that would greatly increase absorbtion. Nitroglycerin is
freely soluble in ether, so should have no problem being absorbed into polyethylene glycol. EDN and nitroglycerin should essentially be the same for
solubilities.
Thread on polyvinyl nitrate
http://www.sciencemadness.org/talk/viewthread.php?tid=1041
Only partially nitrated polyvinyl nitrate could potentially be very insensitive by itself. For example, isopropyl nitrate is very insensitive (it has
been used as rocket fuel) but has a potential detonation velocity of around 5100-5400 m/s. Also to note that the the CH group in the center of
isopropyl alcohol is significantly more vulnerable to oxidation than the CH2 group in ethanol, or 1-propanol. The nitration procedures, therefore for
both PVN and isopropyl nitrate are slightly modified. In the case of polyvinyl alcohol, the sulfuric acid is added first.
[Edited on 13-1-2012 by AndersHoveland]
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DougTheMapper
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MrRedox602, check your U2U.
Victor Grignard is a methylated spirit.
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Pulverulescent
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| Quote: | | I am politely asking the SPOON-FEEDING to STOP! |
'Something of an oxymoron there QS, but you're right ─ as always? 
And it seems that quite a lot of new members don't seem to even know that the site contains a very well-stocked chemistry library!
So perhaps Polverone might consider giving this useful fact more prominence if a revamp is ever planned. 
P
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quicksilver
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Realistically, the collection is positioned prior to login: it's tough to imagine anyone missing it. But perhaps, they do. On a similar subject, my
concern is actually two-fold. If more reading were done it's possible that the essence of the questions would rise in quality and interest. Further,
the "background" information would be included in the question ( Off-hand example: "On Davis's Tetrecene synthesis what level of agitation is required
and would the yield benefit from slight alterations in temperature").
Would it (Library) make a difference if it were repositioned? I couldn't say, however I do know that in certain circumstances, the lack initiation
knowledge has eventually lead to the foremost cause for injury in profession display pyrotechnics (static). In academic O Chem there are lab
assistants, the instructor, or a TA to guide. In hobby chemistry one is most often alone so the demands are great.
The Forum has SO much material that some very tough-to-find questions have been researched and answered. Threshold levels of initiation for energetic
peroxides are low enough so that static which could not be felt can initiate. Thus my opinion that the "Mother of Satan" is not only appropriately
named, but simply too sensitive (& maintain too great a deliquescent nature) to be a reliable primary in any but the most maniacal
self-destructive of purposes. Reading the USBoM background material on testing HMTD would certainly change the minds of most people thinking of
energetic peroxides as utilitarian. There have been studies of the dimer and trimer of TATP in terms of sensitivity and shelf life. It was not
considered seriously due to those demands.
Unfortunately many facets of this hobby are oxymoronic It becomes almost
inescapable when writing.
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MrRedox602
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Back to business. I've been gone for a while, and I have to address some things.
Firstly, quicksilver, I understand your cry to stop the spoon-feeding. While the questions I asked were pretty straightforward and seemingly ignorant,
I had meant to encourage discussion and get peoples' opinion. I didn't exactly ask for a tit to suck on, but I sure appreciate the wealth of
information that was given to me in such a polite and straightforward way. Yes, I do still need to get used to and better utilize the resources
provided here; I'm a 'noob' to this site. I still have a lot to learn about this forum and energetics, for that matter. I should tell you, though,
that I had already downloaded the book that you recommended - it's great, and I'm definitely not done reading through it. The kicker is that I focused
on a much, much better source of information: The Organic Chemistry of Explosives by Jai Prakash Agrawal (Author), Robert Hodgson (Author) [ http://www.amazon.com/Organic-Chemistry-Explosives-Prakash-A... ]. This is available online for free if you do a bit of searching. As for the link
you provided to the unfortunate man who was severely injured, I had already read, reread, and considered what I saw well before you brought it here
for me to see. That's why I was hesitant in considering melting and casting ETN. However, he chose direct heating. I thoroughly understand that
heating and melting is only considered 'safe' if it's pure, and NOT directly heated. All in all, I'm glad I got this out there, and I'm sorry if I
frustrated you.
Anders, thank you for the PVN recommendation. I hadn't considered it until just recently.
Doug, I'll reply via U2U asap.
Thanks, everyone.
"Any problem on Earth can be solved with the careful application of high explosives. The trick is not to be around when they go off." -Valkyrie
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