IndependentBoffin
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High VoD explosives suggestions?
I've been looking to prepare a small quantity of high detonation velocity secondary explosives to act as a very fast switch in an invention of mine.
Ease of manufacture (bearing in mind I am not experienced in organic synthesis), non-toxicity and low sensitivity (including due to contamination by
secondary products (e.g. NOx in conc. nitric acid, lower nitrated products) are my main criteria.
At the moment I've settled on ETN because it seems to satisfy all of the criteria, but I am open to warnings, suggestions and comments 
Can anyone suggest a suitable de-sensitiser and stabiliser for ETN? I intend to use it within about a month of manufacture at most but will be
mechanically manipulating it to various shapes and don't want any accidents
Instead of melt casting it, would slurry casting it work? Mix it with a volatile solvent such as diethyl ether, pour it into a mould and let the ether
evaporate?
[Edited on 1-6-2011 by IndependentBoffin]
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mabuse_
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You will need some primary explosive to set it off properly.
Some people use setups to detonate ETN alone, but I seems to be difficult.
| Quote: |
to act as a very fast switch |
If reaction time is a factor too, you definitely need a primary, otherwise you will always have some unsteady delay.
IMHO you don't need any stabiliser if your ETN is recrystalised and PH neutral.
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IndependentBoffin
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Quote: Originally posted by mabuse_  | You will need some primary explosive to set it off properly.
Some people use setups to detonate ETN alone, but I seems to be difficult.
| Quote: |
to act as a very fast switch |
If reaction time is a factor too, you definitely need a primary, otherwise you will always have some unsteady delay.
IMHO you don't need any stabiliser if your ETN is recrystalised and PH neutral. |
The time between when I flick the switch and when the ETN goes off is not important. The effect I am trying to measure will happen sooner or later.
Hence I was thinking of just using the primary explosives in a blank firearms cartridge, initiated by thermal cookoff from flash powder, to set off
the ETN.
What is important is a very fast shockwave of high shock pressures - hence a high VOD explosive.
Later on I can look into HMTD detonators but frankly I am not comfortable putting any primary explosive into a casing. Blank firearms cartridges are
safer because someone else has done the dodgy filling/pressing business and we do know the cartridges don't tend to go off on a bad day.
I can sell the following:
1) Various high purity non-ferrous metals - Ni, Co, Ta, Zr, Mo, Ti, Nb.
2) Alkex para-aramid Korean Kevlar analogue fabric (about 50% Du Pont's prices)
3) NdFeB magnets
4) High purity technical ceramics
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mabuse_
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To my knowledge priming caps contain a primary explosives to make them sensitive enough.
They LIGHT the propellant charge, but do they deliver a proper shockwave...?
OK, ETN IS quiet sensitive but I doubt that it will detonate properly from that stimulus.
| Quote: |
initiated by thermal cookoff from flash powder |
Could be tricky, as takes some time to heat the cartridge.
I think flashpowder will just wooosh away before the priming cap has reached the right temperature. Better use something that burns slowly.
I would prefer some simple device that hammers the cap.
I think you wont get away without a real primary.
And with that ETN looses it's advantages. In that case PETN is better suited, as it is a little less sensitive (you wrote about mechanical
manipulation...).
[Edited on 2-6-2011 by mabuse_]
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IndependentBoffin
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| Quote: Originally posted by mabuse_ | To my knowledge priming caps contain a primary explosives to make them sensitive enough.
They LIGHT the propellant charge, but do they deliver a proper shockwave...?
OK, ETN IS quiet sensitive but I doubt that it will detonate properly from that stimulus. |
What if the ETN is filled as a powder into the .22 blank?
| Quote: |
| Quote: |
initiated by thermal cookoff from flash powder |
Could be tricky, as takes some time to heat the cartridge.
I think flashpowder will just wooosh away before the priming cap has reached the right temperature. Better use something that burns slowly.
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Magnalium thermite?
| Quote: |
I would prefer some simple device that hammers the cap. |
I could get my workshop to build a spring loaded firing pin to fire the .22 blank....
| Quote: |
I think you wont get away without a real primary.
And with that ETN looses it's advantages. In that case PETN is better suited, as it is a little less sensitive (you wrote about mechanical
manipulation...).
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Pentaerythritol is harder/more expensive to acquire than erythritol.
I can buy it as a commercial company but am looking at a few thousand USD for a minimum order size of a metric ton. I'll probably use a few kg and
then have much hassle trying to dispose of the rest of it
Can't seem to find it in kilo-quantities from my usual lab chemical suppliers, but my list of chemical suppliers is by no means exhaustive.
[Edited on 2-6-2011 by IndependentBoffin]
I can sell the following:
1) Various high purity non-ferrous metals - Ni, Co, Ta, Zr, Mo, Ti, Nb.
2) Alkex para-aramid Korean Kevlar analogue fabric (about 50% Du Pont's prices)
3) NdFeB magnets
4) High purity technical ceramics
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hissingnoise
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| Quote: | | Pentaerythritol is harder/more expensive to acquire than erythritol. |
Since journalists have, of late, developed this questionable habit of referring in print to the PETN used by terrorists, as pentaerythritol,
popping into a crowded pharmacy looking for the stuff could become a disquieting experience for all involved . . .
Pentaerythritol looks good to the syllabically challenged, I suppose!
Here's a patent for a 'safe' detonator!
[edit] I posted the wrong patent-link - the correct patent describes a cap containing nitromannite as base-charge with a flash-producing pyrotechnic
pressed on top of it!
[Edited on 2-6-2011 by hissingnoise]
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quicksilver
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+1 on that issue.
Not only has Pentaerythritol become a focused agenda but it HAS a history of high price for the reagent level material. There is good reason to avoid
the technical / "paint" grade Pentaerythritol that occasionally is available from the vinyl industry as lower nitrated products are typical with that
level of purity.
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IndependentBoffin
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Is pentaerythritol itself a controlled substance in many countries (by law) hence being taken off the shelf or were pharmacies just "persuaded" to
stock alternative chemicals by our fear mongering political masters without a law outlawing it ever being written?
Just trying to gauge whether I will have problems selling on 99% of a metric tonne once I am done with it
Am I likely to have a steady supply of orders for PE from the Sciencemadness community if I were to decide to start selling it?
I can sell the following:
1) Various high purity non-ferrous metals - Ni, Co, Ta, Zr, Mo, Ti, Nb.
2) Alkex para-aramid Korean Kevlar analogue fabric (about 50% Du Pont's prices)
3) NdFeB magnets
4) High purity technical ceramics
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quicksilver
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I had thought you were joking. But I will answer from a wider level so that someone who may not think you were kidding would understand.
Yes, there would be a problem. I would advise individuals not to purchase precursors in commercial volume in any circumstance.
Many years ago typical organic chem classrooms had nitration's as part of lesson planning. A standard was the synthesis of TNT in a under-grad
chemistry lab. However, those days are gone; perhaps for good.
We live the the "age of 911 & 7/7", litigation, & paranoia. It's one thing to have a science-oriented, mature curiosity about energetic
materials and another to purchase ridiculously large amounts of a precursor.
Is pentaerythritol a "controlled substance"? Not in the USA. However there are what is known as "Watch Lists". One exists for DEA another for Homeland
Security. A Watch List chemical may have what is known as "Threshold Limits" or be "Open; No Level" (yes, & List 1, List 2). An example for DEA
would be less than a liter of acidic anhydride, while the ephendrines are watched down to the single dose-level individual retail purchase. DEA &
DHS lists had been published on public basis. However due to efforts to circumvent precursor limits & analog potentials, updates from DEA became
more frequent & troublesome to maintain & distribute. Their individual web sites will contain additional information as to specifics.
NOTE:
There exists (possibly) older watched chemical tables within older threads. It is inadvisable to use dated material as a guideline for understanding
legal ramifications, present day. Please obtain any & all guidelines as currently as possible when making equipment purchases from BOTH a national
and local level.
[Edited on 2-6-2011 by quicksilver]
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gregxy
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A .22 will not work. When hit with a hammer it just burns with a small flame. A primer in a firearm is designed to ignite powder not detonate it.
Some primers give a loud bang but I doubt they are forceful enough to act as a detonator.
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froot
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IIRC according to Van Nostrand's scientific encyclopedia, a mixture of H2 and O2 has a higher det velocity than nitroglycerin, cannot remember the
ratios though. You would set that off with a high voltage discharge (gas barbeque igniter), you can pressurise it, it can fit in any space you provide
it, it is easy, clean and makes water.
And you can reload it on site if the design allows.
[Edited on 3-6-2011 by froot]
We salute the improvement of the human genome by honoring those who remove themselves from it.
Of necessity, this honor is generally bestowed posthumously. - www.darwinawards.com |
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hissingnoise
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| Quote: | | IIRC according to Van Nostrand's scientific encyclopedia, a mixture of H2 and O2 has a higher det velocity than nitroglycerin. |
That would be surprising, though possible, but the VoD of nitro is somewhat dependent on method of initiation, type of confinement, temperature,
volume of explosive, etc . . .
And frozen nitro, though insensitive, has higher VoD than the liquid; EGDN, too, being a mobile liquid, has a higher VoD than nitro!
Frozen EGDN might be expected to have a still higher VoD!
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Microtek
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I find it very hard to believe that any hydrogen/oxygen mix would have a higher VOD than NG. Simply by virtue of being a gaseous mixture, the
propagation velocity of a shockwave must be much lower than that of solid or liquid explosives. I realize that there is more to it than that, but my
doubt remains.
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IndependentBoffin
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| Quote: Originally posted by Microtek | | I find it very hard to believe that any hydrogen/oxygen mix would have a higher VOD than NG. Simply by virtue of being a gaseous mixture, the
propagation velocity of a shockwave must be much lower than that of solid or liquid explosives. I realize that there is more to it than that, but my
doubt remains. |
And, 3 moles of gas reacts to produce 2 moles of gas, some of which may condense.
Unlike conventional explosives that produce excess gas and heat, the only reason why a H2/O2 mixture explodes is because the evolved heat produces an
increase in gas volume.
I wonder whether that is why you get a "pop" in the classic school lab hydrogen test?
Because the expansion of gas is quickly followed by condensation of water vapour and cooling, resulting in an implosion?
[Edited on 3-6-2011 by IndependentBoffin]
I can sell the following:
1) Various high purity non-ferrous metals - Ni, Co, Ta, Zr, Mo, Ti, Nb.
2) Alkex para-aramid Korean Kevlar analogue fabric (about 50% Du Pont's prices)
3) NdFeB magnets
4) High purity technical ceramics
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hissingnoise
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| Quote: | | I wonder whether that is why you get a "pop" in the classic school lab hydrogen test? |
It pops because atmospheric oxygen is very dilute!
Splitting water by electrolysis produces a stoichiometric mixture of the gasses . . .
If you try it, wait until the water saturates and then collect a small quantity of the evolved mixed gasses.
On ignition you won't get a pop . . .
Treat it as if it were a type of nitro which detonates when ignited!
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