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DennyDevHE77
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The oddities of plastic explosives. Recently I made plastic (on PETN) on polybutylene once again. 90\10. If earlier this composition was like a very
steep dough with high density (1.6 g/ml), now the plastic explosive turned out to be very easily compressible, at the same time it crumbles easily and
has low density (1.3). I have not seen this before, even 95/5 compounds were easy to crumble but hard to compress.
The fractional composition is very different, from manually ground into flour, and the smallest crystals obtained by rapid infusion of hot acetone
into water, to quite distinguishable crystals.
So far, my only assumption is that most of the PETN is just too fine and a coarse fraction should be added, but I could be wrong.
Has anyone ever encountered anything like this? When the plastic looks like kinetic sand?
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greenlight
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How have you stored the polyisobutylene? Away from heat, moisture and direct sunlight?
The only thing I can think of at the moment considering the PETN has been prepared the same way is that the PIB has somehow gone bad.
Be good, otherwise be good at it 
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Laboratory of Liptakov
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Denny.....I think you made a mistake when mixing the PIB : Oil ratio. Because PIB is usually added as a 10% solution of PIB in gasoline. But the oil
is added as a 100% solution. A very common mistake is that someone mixes 1 part PIB and 1 part oil. In that case, the effect you described will occur.
Flowing lump......
Development of primarily - secondary substances CHP (2015) Lithex (2022) Brightelite (2023) Nitrocelite and KC primer (2024)
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DennyDevHE77
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I use mouse glue as a source of polymers. Its composition is polybutylene - 80.83% , polyisobutylene - 9.60% , cyclosan - 9.57%. What the latter is,
is not clear, perhaps they are low molecular weight polymers, or a trade name for a crosslinker.... But I think it is just low molecular weight
polymers to give the finished product (glue), more liquid consistency. Or maybe it's really some kind of oil with sebacic/phthalic acid esters. As far
as I understand, production of low molecular weight polymers is not economically feasible, it is much cheaper to dilute high molecular weight ones.
The result will be the same.
I don't use gasoline, as I mix it with my hands, like kneading dough, and then roll it out with a rolling pin. And I don't use oil, because I think
that would make it really snotty.
Right now, to illustrate my words with a photo, I decided to make a small sample of plastic. But I took an old tube of glue. And this time, the same
PETN came out with a normal plastic explosive. Much harder, requiring a strong hand pressure for molding. I measured the density, it came out 1.56.
Apparently, I got a defect. And the new mouse glue is apparently too liquid.
In any case, I now have to either check the glue after purchase, or try to heat it so that all the volatile from it evaporated ....
I still want to put a second coarse fraction of crystals into the plastic. But the problem is that the crystals in it are 0.25-0.5mm. I'm afraid that
such large crystals can trivially not detonate.....
[Edited on 1-12-2023 by DennyDevHE77]
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MineMan
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Quote: Originally posted by DennyDevHE77  | I use mouse glue as a source of polymers. Its composition is polybutylene - 80.83% , polyisobutylene - 9.60% , cyclosan - 9.57%. What the latter is,
is not clear, perhaps they are low molecular weight polymers, or a trade name for a crosslinker.... But I think it is just low molecular weight
polymers to give the finished product (glue), more liquid consistency. Or maybe it's really some kind of oil with sebacic/phthalic acid esters. As far
as I understand, production of low molecular weight polymers is not economically feasible, it is much cheaper to dilute high molecular weight ones.
The result will be the same.
I don't use gasoline, as I mix it with my hands, like kneading dough, and then roll it out with a rolling pin. And I don't use oil, because I think
that would make it really snotty.
Right now, to illustrate my words with a photo, I decided to make a small sample of plastic. But I took an old tube of glue. And this time, the same
PETN came out with a normal plastic explosive. Much harder, requiring a strong hand pressure for molding. I measured the density, it came out 1.56.
Apparently, I got a defect. And the new mouse glue is apparently too liquid.
In any case, I now have to either check the glue after purchase, or try to heat it so that all the volatile from it evaporated ....
I still want to put a second coarse fraction of crystals into the plastic. But the problem is that the crystals in it are 0.25-0.5mm. I'm afraid that
such large crystals can trivially not detonate.....
[Edited on 1-12-2023 by DennyDevHE77] |
I don’t know.
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dettoo456
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If the material is acting like kinetic sand you probably have too low viscosity/too much liquid-like material instead of rubbery solids in your mix.
Also, dropping the particle size will probably help to make your PBX more malleable as it’ll increase the surface area on which the binder (PIB
rubber) can adhere to. High MW PIB can be hard to find, especially in consumer products and the rat glue probably isn’t even high enough MW. One
source of PIB that I found might work is the glue/adhesive tape on steel drum (like 40 or 55 gal) lids. It’s used to hold the rubber gasket/seal to
the lid. If you pull the gasket off you should be able to see it.
C4 used to use EXXON Vistanex which has a really high MW - even higher than any BASF PIB. The PBX mainly relies on high MW rubber loadings with
mineral oil (or some low viscosity PIB) and DOS to give malleability.
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dettoo456
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| Quote: Originally posted by dettoo456 | If the material is acting like kinetic sand you probably have too low viscosity/too much liquid-like material instead of rubbery solids in your mix.
Also, dropping the particle size will probably help to make your PBX more malleable as it’ll increase the surface area on which the binder (PIB
rubber) can adhere to. High MW PIB can be hard to find, especially in consumer products and the rat glue probably isn’t even high enough MW. One
source of PIB that I found might work is the glue/adhesive tape on steel drum (like 40 or 55 gal) lids. It’s used to hold the rubber gasket/seal to
the lid. If you pull the gasket off you should be able to see it.
C4 used to use EXXON Vistanex which has a really high MW - even higher than any BASF PIB. The PBX mainly relies on high MW rubber loadings with
mineral oil (or some low viscosity PIB) and DOS to give malleability. |
Pardon my earlier post, the adhesive used to hold gaskets in 55gal drums is actually likely Styrene-butadiene. The styrene-butadiene itself can still
be used in PBXs though, it just needs a suitable solvent.
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MineMan
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I thought silicone worked well? Wesson smith used it
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dettoo456
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I believe Wesson smith used HTPB and/or lithium grease in his formulations but he may have mentioned silicone before. Silicone can be used but it will
cure and you’ll be left with a rubbery puck instead of a plastic material. Also, the issue with lithium grease is that it doesn’t have any
tack/binding ability, only plasticizing ability.
Styrene, HTPB, PIB, Viton, and even something like asphalt are the only real choices for a good PBX since they provide both plasticizing and binding
ability on their own (high MW polymers need an oil though - to lower viscosity).
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DennyDevHE77
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Do you think it is possible to grind PETN in a coffee grinder as follows. Mix PETN and, for example, sugar in a ratio of 20 to 80. We grind it in
several steps (as the mixture gets noticeably warm when grinding for a long time), and then just dissolve it in hot water, all the sugar goes into the
water, and the PETN is filtered out.
Do you think such a mixture can detonate at all?
If anyone has played with PETN like this before, please write back (you survived, right?).
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dettoo456
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Don’t blend any explosive in a coffee grinder. Insensitive oxidizers and fuels (kept separate of course) can be ground; i.e. KNO3 or Al. If
anything, a slurry of PETN in water may be run in a ball mill at low speeds but definitely not a coffee grinder. PETN may release oxygen and other
nitrogen oxides at higher temperatures when being physically broken down, these can oxidize the reducing sugar and potentially cause a deflagration or
detonation. Not to mention, if the seal between the cutting blade and the inside of the grinder isn’t tight enough, some powder may fall in and make
direct contact with the grinder’s motor and internal circuit, potentially causing a fire, and/or a detonation from DDT.
PETN crashed out via the anti-solvent method (Acetone or alcohol into water) should yield plenty small enough crystals. If that doesn’t work, try to
buy a TLC sprayer and spray a solution of PETN onto a cooled sheet of something like PTFE, then carefully scrape off the dried powder.
Plenty of methods to yield small particle EMs exist, but the mechanophysical methods are usually the least safe.
[Edited on 1-1-2024 by dettoo456]
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Laboratory of Liptakov
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dettoo has truth....Methode acetone or alcohol / water provide plenty small crystals itself (agglomerates) . Maybe you can use stainless sieve 1x1 mm.
For bigger parts. In water bath you can PETN slowly crushed thru sieve under water level.....
Development of primarily - secondary substances CHP (2015) Lithex (2022) Brightelite (2023) Nitrocelite and KC primer (2024)
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DennyDevHE77
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Thanks for your previous replies, I still don't think petn would explode at a 20 to 80 ratio, but the fact that it could start decomposing doesn't
make me happy, because that's a loss of yield.
But here the following question has arisen, how to make up optimal ratios of nitric acid (57%) and phosphorus pentaoxide for distillation? It would
seem that it is not easier, just take the molar ratios of the reaction. But this way is obviously not optimal, because during distillation pyro and
meta phosphoric acids will be formed, which pull water even stronger than sulfuric acid, so in the end the amount of phosphorus pentaoxide can
probably be significantly reduced. But I have no idea how to calculate that.
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dettoo456
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P2O5 will dehydrate HNO3 all the way to N2O5, which isn’t even needed for PETN or any other aliphatic nitrate ester. You can use either WFNA or
NH4NO3/H2SO4 for PETN and you won’t need to waste P2O5.
Metaphosphoric acid (obtained from aggressively heating H3PO4 at around 500C until white fumes are emitted and a gel is left over) can dehydrate H2SO4
to SO3/H2SO4 but I haven’t seen the same reaction demonstrated with HNO3 -> N2O5/HNO3. You can try to do this, but IMO it’s a waste if you have
access to nitrate salts, H2SO4, and/or 69% HNO3. The Metaphosphoric acid dehydration pathway is only useful if you have already high concentration
mineral acids and need close-to-anhydrous acids; which most people don’t. Plus, if you can get P2O5 for cheap, you’d likely be able to find NH4NO3
as well, and that’s much more useful in EM synthesis.
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DennyDevHE77
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Well, I have access to NH4NO3, but I use it most often as a component of mixed explosives. Sulfuric acid is relatively cheap to me, but it is sold
sub-accountably. Phosphorus pentaoxide, like nitric acid (58-70%) is sold absolutely freely, although P2O5 is three times more expensive than sulfuric
acid. Of course, if I could get tens of liters of sulfuric acid, I would not ask myself this question, but I can only get tens of kilograms of
phosphorus pentaoxide, and sulfuric acid is more limited for me.
Yes, P2O5 dehydrates nitric acid to N2O5, but only anhydrous, if it is an azeotrope (68%) then water will be removed first, either directly or the
resulting N2O5 will react with water.
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DennyDevHE77
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Guys, could someone please point me to the critical diameters of cast ETN, TNT, and picric acid? I found only for TNT, and that, in different sources
it is indicated from 25 to 40 mm.
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OneEyedPyro
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| Quote: Originally posted by DennyDevHE77 | | Guys, could someone please point me to the critical diameters of cast ETN, TNT, and picric acid? I found only for TNT, and that, in different sources
it is indicated from 25 to 40 mm. |
ETN is 8 to 10mm depending on who you ask. I can't really say about TNP but given its higher power and sensitivity I'd guess lower than TNT. I
remember seeing a diagram where pressed picric acid was used as a booster in impact fuse assemblies for small mortars by some country back in WWII
(France maybe?). In any case, the diagram showed the booster portion being relatively small in diameter, maybe 20mm.
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DennyDevHE77
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I'm a little surprised. pentolite (50% PETN, 50% TNT) has a critical diameter of 6.7 mm. On the other hand, pentolite is not homogeneous in its
consistency, so maybe this has an effect.
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Sir_Gawain
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Small irregularities such as bubbles and cracks greatly increase the sensitivity of an explosive. Also, my EBW detonators have a 6.4 mm ID with pure
ETN, and they definitely go high order.
“Alchemy is trying to turn things yellow; chemistry is trying to avoid things turning yellow.” -Tom deP.
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OneEyedPyro
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| Quote: Originally posted by Sir_Gawain | | Small irregularities such as bubbles and cracks greatly increase the sensitivity of an explosive. Also, my EBW detonators have a 6.4 mm ID with pure
ETN, and they definitely go high order. |
I've made little caps with pressed ETN and SADS in those stirring straws you get with coffee or at a bar with mixed drinks. They're maybe what, 2.5mm
inner diameter? Too small for a standard visco fuse to fit inside.
I still got a full detonation every time, but I only made several. Had I tried dozens I'm sure some would have failed. Had the straw been 20 meters
long instead of 2cm long the detonation would have certainly fizzled out before reaching the end.
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ManyInterests
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I have a question about storing liquid explosives such as nitroglycerine, ethylene glycol dinitrate, propylene glycol dinitrate, and diethylene glycol
dinitrate.
Is it safe to store such material in PET bottles? The same bottles that water and soda is stored in? I plan on makying DEGDN since it is safer to
handle than NG and also even less volatile (from Urbanski's books), but is hygroscopic, so drying it and storing it to stop any moisture absorption
will mean I will need to stop it in a semi-open bottle in another container. Does it need glass or will any plastic suffice?
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dettoo456
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I definitely wouldn’t store in glass, simply due to the risk of shrapnel in a DDT situation (though rare). If you dissolve it in something like DCM
though, glass might be alright as long as you vent it every once in a while.
If you store pure, HDPE should work. It is pretty much the standard for storing dry EMs and would likely be fine with liquids. I couldn’t find much
info relating to storing EGDN, but, on page 7 of the attached doc, the author mentions potential issues of HDPE relating to interactions of nitrate
esters w/plasticizers.
https://apps.dtic.mil/sti/tr/pdf/AD0778207.pdf
I’d test at small scale before storing anything >1g, just in case.
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ManyInterests
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I never intend to store anything but pure. But if storage is an issue, then I will make as needed.
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underground
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Does Calcium Cyanate (CaOH and Urea reaction) and Hydrazine Sulphate produce semicarbazide ?
[Edited on 28-3-2024 by underground]
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Nemo_Tenetur
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Anyone here with carbodihydrazide synthesis experience? I require a larger quantity as precursor for different energetic materials and I don´t want
to buy it because I´m a cheapskate. Fisher scientific sell it for 450 Euro per 500 gram, that´s a ripp off.
There are different routes, phosgene as precursor is out of question. Cyanuric acid and Propylene carbonate are mentioned in patents as better
yielding and purer product than urea, but the latter is unbeatable cheap (about 100 euro / 50 euro per kilo versus less than 2 euro per kilo for
fertilizer grade).
The yield ist not decisive for me, but the purity (or more precise, the ease of purification) of the final product. The available information is
pretty sparse about purity and purification with respect to the different routes. So input and comments about the different routes are welcome. I
have enough glassware, fume hood, two stage vacuum pump etc. and 80% hydrazine hydrate in stock.
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