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Author: Subject: Awful ETN yields
XeonTheMGPony
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[*] posted on 15-1-2020 at 04:21


Quote: Originally posted by LardmanAttack  
Quote: Originally posted by XeonTheMGPony  
Spend more time learning about the reaction, why it does what it does.

1h of study will save you pounds of wasted chemicals and hours in wasted time and effort

Take notes of the reaction, then each one there after making particular notes of changes and how they effected the yield, change one variable at a time.

Mixing, never enough mixing!


Use a slight excess of H2SO4 to facilitate easier mixing if needed.

http://www.sciencemadness.org/talk/viewthread.php?tid=83358

http://www.sciencemadness.org/talk/viewthread.php?tid=7209



[Edited on 13-1-2020 by XeonTheMGPony]


I know how the reaction works, I know chemistry, i'm not a complete amateur. I was just initially annoyed at how it wasn't working correctly, its not like if you know the chemistry, your yields will automatically be perfect.

If I really need to prove it to you then fine.
Erythritol is a sugar alcohol with a molar mass of 122.120 g·mol, when added to a solution of nitric acid and sulfuric acid in the correct ratios, a reaction called a nitration takes place, whereby the hydroxyl groups of the Erythritol are replaced with Nitro groups (NO2) thus creating a new, explosive compound named Erythritol tetranitrate, Its explosive properties coming from the newly created NO2 groups and their ability to explosively decompose while oxidizing any reductive elements (mainly carbon and hydrogen) in the chemical structure, thus creating a large amount of gases in a short time

There. I know chemistry, although I can admit I'm a little rusty at stoichiometry.


Well you proved you deff need to do a lot of refreshing!

Why I provided you to two of the largest thread links on this exact question, that goes into detail for this particular. reaction, and optimizations

Even I had issues when I started making this, part is it turned out one of my feed stocks wasn't pure enough, the next was my mix was slightly out of spech, and three there where improvements in procedure I hadn't considered till reading of others methods.

So I do what I all ways do when I get surprising poor results, I research the shit out of the reaction to see where I screwed up! and if I didn't screw up I look more carefully at my reactants and ratios (Well I do that any ways).

I don't care if you know or not, my point was as clear as day, you need to review this stuff! If you are getting bad results we need to eliminate variables, I all ways start with the person as they tend to be the biggest problem in 99.99999999998% of things!

Our brains are crap at remembering things, we often forget simple basic things that have the ability to toss a rather big wrench into the works, and unless you review the basics, how do you know, that you don't know that you don't know! Less you refresh your memory! Yes it is tedious, but when you play with a thing where lucky is only losing limbs, it is well served to be thorough, I find a stout hot coffee helps with the process!

SO if you want improved results with better yields follow instructions!

Step one: Review your knowledge base, look up the basics.
Step two: Review the threads on others problems, look for common themes.

Step Three: Check all reagents, purify if need, or concentrate if needed, dry if needed.

Step four: Check glass wear, clean and contaminate free?

Step five: review your procedure and compare it to what you learned from every one else's screw ups (Including mine that are in the thread!)

Step Six: Take all this information and design a test run experiment, hone in one the sweet spot with your reagents and scale up slowly whilst keeping track of the process in lab book.

there is no magic thing, we can't say "Just throw this in there and get 200% yields!"

[Edited on 15-1-2020 by XeonTheMGPony]
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LardmanAttack
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[*] posted on 16-1-2020 at 01:31


Quote: Originally posted by Tsjerk  
Not exactly, you form nitrate groups, not nitro groups. Despite confusing naming all around, they are quite different.

Being "rusty" at stoichiometry sound a bit strange to me. You get it or you don't, it is secondary school stuff for 14 year olds..


Alright, I didn't come here to debate whether or not I know chemistry, the point is, i'm getting good yields now and am satisfied. Thanks for everyone's help.
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LardmanAttack
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[*] posted on 16-1-2020 at 01:35


In the end, I think my biggest issues were 1. not enough time letting it react, 2. too much water and 3. too little nitrate/nitric, Now that i've solved all of those problems my yields are 1.5x the original amount of Erythritol.
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[*] posted on 17-1-2020 at 02:32


Quote: Originally posted by LardmanAttack  
In the end, I think my biggest issues were 1. not enough time letting it react, 2. too much water and 3. too little nitrate/nitric, Now that i've solved all of those problems my yields are 1.5x the original amount of Erythritol.


Good for you. I could recommend you the first article in the thread "Life after detonation"




Women are more perilous sometimes, than any hi explosive.
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Brightthermite
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[*] posted on 22-3-2020 at 21:13


Quote: Originally posted by XeonTheMGPony  
Some actual information would be nice, like how long, temps maintained, total volumes, stirring method.

There is two massive threads on here dedicated to ETN.


I keep searching for these threads and cannot find them, could you provide a URL?
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[*] posted on 23-3-2020 at 03:18


Quote: Originally posted by Brightthermite  
Quote: Originally posted by XeonTheMGPony  
Some actual information would be nice, like how long, temps maintained, total volumes, stirring method.

There is two massive threads on here dedicated to ETN.


I keep searching for these threads and cannot find them, could you provide a URL?


They are in the post from XeonTheMGPony at the top of this page.
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Brightthermite
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[*] posted on 25-3-2020 at 19:59


I just synthesized some ETN using tips from this thread. It readily detonates to thermal shock but is not hammer sensitive AT ALL. Is this an indication of poorly made ETN or just well washed and stable?
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MineMan
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[*] posted on 26-3-2020 at 03:40


The thing about EMs... they can seem very insensitive one day... but not the next. A little dirt on the hammer, change the surface, or, hammer angle and boom.

It is a secondary. Kind of... really between the two... but yes, you have the right stuff
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greenlight
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[*] posted on 26-3-2020 at 11:35


Impact and friction are both thermal shock. Initiation is from energy transferred from the hammer (or whatever else is used) to the explosive and forming hotspots from intercrystalline friction (initiates primaries) and compression of gas spaces in between crystals (mainly initiates secondaries).
If the resulting thermal energy absorbed is higher than what is dissipated and lost to the surroundings, initiation occurs around this point. Explosives are pretty shit thermal conductors.

@Mineman is right, somedays good behaviour is observed, other days not so much:cool:

Some factors I can think of which would influence the results:

* Purity
* Crystal size and internal structure (voids)
* Moisture presence
* Ambient air surroundings
* Impact surfaces material and surface texture
* ETN recrystallized?
* and obviously impact energy





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MineMan
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[*] posted on 27-3-2020 at 02:24


Quote: Originally posted by greenlight  
Impact and friction are both thermal shock. Initiation is from energy transferred from the hammer (or whatever else is used) to the explosive and forming hotspots from intercrystalline friction (initiates primaries) and compression of gas spaces in between crystals (mainly initiates secondaries).
If the resulting thermal energy absorbed is higher than what is dissipated and lost to the surroundings, initiation occurs around this point. Explosives are pretty shit thermal conductors.

@Mineman is right, somedays good behaviour is observed, other days not so much:cool:

Some factors I can think of which would influence the results:

* Purity
* Crystal size and internal structure (voids)
* Moisture presence
* Ambient air surroundings
* Impact surfaces material and surface texture
* ETN recrystallized?
* and obviously impact energy



Green light. Why then do all aluminized explosives show a significant mark in sensitivity rise. Al is the 4th best conductor of heat..

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[*] posted on 27-3-2020 at 06:23


That's a really good question, I did some research and;
I think the fact that the aluminium only makes up a small percent (5-30%) of the explosive mixture and that it is in the powder form and mixed with explosive as well makes a difference compared to if it is solid aluminium.
The thermoconductivity (watts per meter-kelvin) K value for pure aluminium is 205.0. The results table I uploaded below shows maximum K value for RDX with 30% aluminium is only around 0.140, only a small fraction of pure aluminium. HMX with 30% aluminium is slightly higher with 0.175. This does not improve the thermal conductivity much at all. But does not explain why the aluminized explosives have higher sensitivity.


My best explanation for that would be:

Secondaries are initiated from compression of gas spaces causing extreme pressure and high temperature in between the crystals when subjected to shock by impact. Maybe the higher sensitivities are due to the hardness and density of the aluminium powder confining these micro gas bubbles more than just the powdered explosive on its own.

Primary explosives are initiated before the gas compression can happen from what I have read. Because they are set off by heat energy, the inter-crystalline friction forms hotspots and causes initiation first. I bet adding aluminium to primaries causes sensitivity to increase exponentially.

[Edited on 27-3-2020 by greenlight]

Screenshot_20200327-214807_Gallery.jpg - 161kB

[Edited on 27-3-2020 by greenlight]

[Edited on 27-3-2020 by greenlight]




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[*] posted on 27-3-2020 at 09:28


Regarding what Mineman said, for several months I was making very small batches of TATP, only a few hundred mg at a time since I know it is not the most stable of primaries. I would take maybe 30 mg or so something on that order and put it in a pile and "detonate" it with my high power blue laser at a distance. It would just make a nice low order poof, and no fuss. I did this literally maybe 100 times. Then I made another batch, same as ever I thought. I put out the pile, and it went high order on me. Ears ringing, wife yelling from upstairs, dog barking.... There was no actual harm done, since I am pretty cautious and using small amounts always. But as to WHY it went high order that time I have no clue at all. Needless to say I stopped doing that!
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[*] posted on 28-3-2020 at 11:35


The ETN was not recrystallized, just well washed. Flour white, not yellow in it at all. And I am speaking of a thermal shock in the sense of rapid heating with a flame. I agree that impact and friction are both forms of thermal shock, however a flame (from Rcandy) I would say transfers much more energy and is not just localized to a single impact point.

In regards to aluminum sensitizing explosives:
I was at a job fair once and asked a recruiter (they were recruiting organic chemist/engineers) of BAE Systems just what MineMan asked, why did aluminum increase sensitivity in explosives such as AN and increase power. He explained that the introduction of a hard powder like that increased friction as well as kinetic energy transfer. Using sand or glass abrasive beads the same effect can be achieved, aluminum is often used because it not completely inert.
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[*] posted on 29-3-2020 at 00:20


Quote: Originally posted by greenlight  
That's a really good question, I did some research and;
I think the fact that the aluminium only makes up a small percent (5-30%) of the explosive mixture and that it is in the powder form and mixed with explosive as well makes a difference compared to if it is solid aluminium.
The thermoconductivity (watts per meter-kelvin) K value for pure aluminium is 205.0. The results table I uploaded below shows maximum K value for RDX with 30% aluminium is only around 0.140, only a small fraction of pure aluminium. HMX with 30% aluminium is slightly higher with 0.175. This does not improve the thermal conductivity much at all. But does not explain why the aluminized explosives have higher sensitivity.


My best explanation for that would be:

Secondaries are initiated from compression of gas spaces causing extreme pressure and high temperature in between the crystals when subjected to shock by impact. Maybe the higher sensitivities are due to the hardness and density of the aluminium powder confining these micro gas bubbles more than just the powdered explosive on its own.

Primary explosives are initiated before the gas compression can happen from what I have read. Because they are set off by heat energy, the inter-crystalline friction forms hotspots and causes initiation first. I bet adding aluminium to primaries causes sensitivity to increase exponentially.

[Edited on 27-3-2020 by greenlight]



[Edited on 27-3-2020 by greenlight]

[Edited on 27-3-2020 by greenlight]


Thank you for doing that research! I was under the impression 30 percent aluminum could increase heat conductance by a lot...Chris Mochella mentions that 1 percent graphite can reduce the static sensitivity of pyro mixtures.... yet metal powdered mixtures are the worse.

I am really beginning to doubt the hot spot theory... it just does not make sense to me. That ANFO when shot will a bullet does not det... yet if micro balloons are added... that a sphere of .01 mm can generate enough heat and conduct it to proceed the reaction front. I feel another mechanism is at work.
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[*] posted on 30-3-2020 at 20:27


@Brightthermite
Generally sensitivity is directly correlated with heat of explosion of the EM. EM with very positive(e.g. AN)/negative(e.g. TNT) OB will be insensitive. Reason is low H_of_E EM need a thick layer of reacting material to energize the detonation wave. This means they have large critical diameter/high initialization energy => insensitive.
Molecular structure place a role here too(e.g. OB zero ONC is insensitive). So heat of explosion should be considered as rule of thumb.

Back to why aluminum sensitize AN/ETN. Both are OB positive, and add Al increase H_of_E and thus lower critical diameter/initialization energy. AN has infamous low H_of_E, adding just about any fuel to it will greatly enhance it sensitivity.
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[*] posted on 15-4-2020 at 12:37


Nitrate salt may just be better than nitric acid in this synthesis. Possibly because of the non-existent water content in dry salts. Plus, nitrate salts are cheap and widely available while nitric acid is expensive and harder to get. Plus, some syntheses require strong nitric acid, so I’d save the acid for syntheses that require it.

That said, more concentrated nitric acid, or more concentrate sulfuric acid (or just more sulfuric acid) may improve yields if too much water is indeed the problem.
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[*] posted on 29-5-2020 at 21:05
Failed Sulfuric Acid + Ammonium Nitrate Bath


Question: If the temp of a nitrate bath gets to high can it reduce its ability to nitrate?

I was making some ETN today the same way I always do it. 56 ish ml of 93% sulfuric acid is mixed with 40 grams of ammonium nitrate (crushed with a mortar and pestal) to form the nitrating bath for 10 grams of erythritol. This normally yield 14-15 grams of ETN. I normally mix these two outside of an ice bath slowly and the temp rises to between 25-30 C. This time however they were mixed rapidly and the temp shot up to above 40 C. I then placed it in an ice bath to cool to 5 C. I introduced the erythritol outside of the ice bath (stirring the whole time) for 10 min, temp rose to 25 C. It was then placed in an ice bath for 30 min. The liquid never thickened like it normal does and i was left with an awful yield. Around 4 grams.
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