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Laboratory of Liptakov
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[*] posted on 29-11-2023 at 04:50


Because aluminum has a much higher thermal conductivity than iron. Aluminum dissipates heat from the grinding area so quickly that this area does not have time to heat up to an ignition temperature.



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DennyDevHE77
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[*] posted on 30-11-2023 at 20:42


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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[*] posted on 1-12-2023 at 06:09


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.




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[*] posted on 1-12-2023 at 08:05


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......:cool:



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[*] posted on 1-12-2023 at 09:28


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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[*] posted on 3-12-2023 at 23:41


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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[*] posted on 6-12-2023 at 11:37


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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[*] posted on 11-12-2023 at 11:36


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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[*] posted on 12-12-2023 at 01:04


I thought silicone worked well? Wesson smith used it
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[*] posted on 12-12-2023 at 13:10


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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[*] posted on 1-1-2024 at 07:21


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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[*] posted on 1-1-2024 at 11:30


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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[*] posted on 2-1-2024 at 01:38


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.....:cool:



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[*] posted on 5-1-2024 at 05:07


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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[*] posted on 5-1-2024 at 15:30


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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[*] posted on 6-1-2024 at 01:09


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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[*] posted on 8-1-2024 at 11:55


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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[*] posted on 13-1-2024 at 07:44


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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[*] posted on 28-1-2024 at 20:19


Quote: Originally posted by OneEyedPyro  
ETN is 8 to 10mm


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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[*] posted on 29-1-2024 at 16:32


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.



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[*] posted on 30-1-2024 at 14:22


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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[*] posted on 12-3-2024 at 14:01


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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[*] posted on 12-3-2024 at 14:51


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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[*] posted on 12-3-2024 at 20:24


I never intend to store anything but pure. But if storage is an issue, then I will make as needed.
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[*] posted on 27-3-2024 at 10:19


Does Calcium Cyanate (CaOH and Urea reaction) and Hydrazine Sulphate produce semicarbazide ?

[Edited on 28-3-2024 by underground]
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