Pard
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Using less and making smaller batches (PETN)
Hello
Is it possible to use less when following certain synthesis? Specifically PETN. The one I read calls for this:
32.7 ml of 70% HNO3 (75% excess)
18.9 ml of 96% H2SO4
10 g of Pentaerythrite
Now this does a project yield of over 20grams, Is it possible to use half the amounts or do I need to take other factors into account?
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Turner
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Yep you can do that.
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Pard
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Thank you turner. So is it safe to do it with nitrating mixtures, as opposed to something that requires a catalyst like the organic peroxides. Would
be nice to do a scaled doing EGDN lot
While I've got the thread going, is there any formula for working out the yield of a projected EGDN, MEKP or NG synth? Is it relative to the ethylene
glycol or something perhaps? Most synths call for a worrying large amount and I'm not comfortable with such high amount, nor do I want to just cut in
half the portions provided without the okay.
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Turner
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You may use an excess of reagents to move the reaction to the right in some cases, but familiarize yourself with what a mole is, it is quiet cool once
you can see how it is applied so often.
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Turner
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If I were you, and you're interested in that type of thing, read about some basic chemistry on the internet about moles, reactions and stoichiometry.
Once you understand exactly what is happening, you'll enjoy it a bit more.
1mole of ethylene glycol needs 2 moles of NO3, (whether you use NH4NO3, HNO3, or what have you you will use 2 moles of this)
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underground
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I do not want to open a new thread with only a simple question so i am asking here, and the question is about the moles.
For example
3 moles of ETN and 2 moles of NM has a zero OB
3 C4H6N4O12 + 2 CH3NO2 = 14CO2 + 12H20 + 7N2
So we have:
302.11x3= 906,33gr of ETN and
61.04x2= 122.08gr of NM
Now if i just want to prepare only 1gr of that mixture and divide them with 100 so we will have now 0.90633gr of ETN and 0,12208gr of NM it sould work
correctly that is correct ?
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Turner
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yep, keep the ratio and it will be OB
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underground
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Thanks!
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Pard
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Quote: Originally posted by Turner  | If I were you, and you're interested in that type of thing, read about some basic chemistry on the internet about moles, reactions and stoichiometry.
Once you understand exactly what is happening, you'll enjoy it a bit more.
1mole of ethylene glycol needs 2 moles of NO3, (whether you use NH4NO3, HNO3, or what have you you will use 2 moles of this)
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Yeah have have told to read this before. I've started trying but can anyone put to me a good PDF for introductary stoichiometry. I'm not expecting to
be spoon fed, but if someone held me and fed me by the spoon I wouldnt complain
I think it'd be helpful. I've tried learning on my own but my ADD gets in the way. It make pageful of infor look lie chicken lines
for those interested this was my procedure (1/2 of made famour powerlabs one):
I started with the following:
16.3c of 70% HNO3
18.9 of 96% H2S04
5g of pentaerythrite
I stuck the mother bottles of acid in the fridge to give headstart. Then is measure off the acids and placed them in small flask with caps to go into
the freezer to cold. Eventually I take out and slowly combine while monitoring temp to keep below 25C
Eventually when they're mixed and my is satisfied I weight out 5g of pentoerythrite in separate piece of paper (a little bit goes a long way, it is
heavy) The nitrating mixture is in salted ice cube bath. I begin to add .75 - 1g at a time, taking care to monitor temp and stir. This make it go
white. Eventually is all added and I contintue to stir. Right now is thick mixure not unlike white porridge
I continue to stir for 15 minute after last is added. it is now really thick mixture. Right now I remove from ice bath and put in hot water bath
that's 45C roughly (more real it sat at about 40 - 45C) - it stays for 25 minutes. I noticed at this stage the fumes began to come off, Not runawa
nitration fumes but a little bit of dark orange / red fumes are appear. If I let mixture just sit, they build up and appear to colour slurry.
Especially if I stir. but I had fan on them clearing them out and they disappear.
Next mixture is dumped into 450mls of ice cold water. The yield is now apparent. I decant off a little water that is clean, the PETN sits on the
bottom of the beaker causing no trouble. There is lots of stuff in water. I filter it through lab filter and run clean water over it, then eventually
I run hot bicarbonate solution over it.
Next 100ml of acetone is palced in warm bath, not akin to the one the mixture sit is in (50C) - I add in the crude PETN powder and stir util
dissolves. Next I crash acetone / petn mixutre in poured into 600ml cold water beaker. PETN precipitates and becomes see in glass. Its look reminds of
of TATP.
I allow to settle and filter in filter paper and funnel, saving the powder which, while still in the filter is placed on tissue paper and news paper.
Eventually it is scratched off filter paper and put on bleached printer paper and eventually spread out, then next to i
OVERALL YIELD: 8 grammes
Not bad for a first attempt. I hear double the quantity of pentaerythritol is normal. This was someone who isn't me's first attempt at nitration. The
slurry appeared to me to be fuming so I acted quickly.
All in all, here is score
2/5 - yield (is my fault. My first try
5/5 - for easy to follow
4/5 - for accesible ingredients
5/5 - for Ease of processs and end result
?/5 - for effectiveness (hasn't been tried yet.
I don't know why more people don't do this as opposed to dealy TATP or HMTD. Well I guess certain things are hard in certain country. But here Nitric
and Sulfuric acid are easy to buy and pentoerythril is bought from Ebay at 98% purity from big time seller. No excuses to blow yourself up. Even RDX
is easy to make
[Edited on 10-1-2014 by Pard]
[Edited on 10-1-2014 by Pard]
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Pard
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Also, using PETN as a base charge, is it posible to0 use a minicscle amout of TATp (HMTD reacts with aluminum which is the material i use
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roXefeller
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| Quote: Originally posted by Pard | | I've started trying but can anyone put to me a good PDF for introductary stoichiometry. I'm not expecting to be spoon fed, but if someone held me and
fed me by the spoon I wouldnt complain |
I'm not sure what your question is in this post. If you are wondering what the stoich analysis is for this problem here is an attempt:
For PentaErythritol: 5g/136.15 g/mol (the molar mass of PE from wikipedia) = 0.03672 mol
In the ideal case one molecule of PE gets four nitrate esters giving the final molecule a molar mass of 316.14 g/mol. This is 136.15 +4x(62.0049
g/mol of nitrate) - 4x(17.008 g/mol of hydroxyl). The last term is because the nitrate group replaces the hydroxyl group during nitration.
The nitric acid and sulfuric acid are expected to be excess reagents. Almost all reactions are chosen to have a species that will run out and others
that will have extra. In this case PE is the limiting species, all the PE should be used up.
The number of moles of nitric acid is as follows:
The volume of dilute HNO3 must be converted to grams of actual HNO3 molecules.
We use specific gravity (SG) which means the density of the acid is SG x water_density at the same temp. The density of 70% HNO3 is then
1.4134 (SG of 70% at 20C http://handymath.com/cgi-bin/nitrictble2.cgi?submit=Entry)
x 0.998203 g/cc (density of water at 20C http://www2.volstate.edu/chem/1120/Molarvol.html)
=1.41086 g/cc. This is grams of solution per cc of solution.
16.3 cc of 70% HNO3 x 1.41086 g/cc
= 22.997 g 70% HNO3 solution.
But only 70% of solution is HNO3:
22.997 g x 0.70 = 16.0979 g pure HNO3 in 16.3 cc of acid
The moles of HNO3 is 16.0979 g / 63.01 g/mol (wikipedia) = 0.25548 mol HNO3.
This is almost 7x (0.25548/0.03672) the number of moles of PE, and in the ideal case only 4x is needed, so you can see it is in excess.
This is because reactions aren't ideal, but we compare the final product yield to the ideal nonetheless.
So if all the PE was converted to PETN, the 0.03672 moles of PE would become 0.03672 moles of PETN (each molecule of PE becomes PETN).
The 0.03672 moles of PETN weighs 11.61 grams (0.03672 mol x 316.14 g/mol molar mass of PETN).
So if you pulled off 8 grams, you got a yield of 69% (8g actual/11.6 g theory).
I'm only writing this because you said you are struggling with stoich, so ask for help if it isn't clear enough. I even messed this up as I typed it
because I'm a little tired, but checking math certainly helps.
[Edited on 10-1-2014 by roXefeller]
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Pard
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Thank you. Sorry english isn't my first language to speak or write. Thanks for the information too. The question I asked was if there was some
resources I could read. PDFs or otherwise. Will read over what you have told me
So can anyone answer me whether a small amount of TATP is applicable for use in caps, like one might use SA,DS or Lead Azide. I'd say HMTD but it's
too reactive with metal.
[Edited on 10-1-2014 by Pard]
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DubaiAmateurRocketry
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Umm its always more economic to use less acids in synthesizing nitrate esters, is there any paper covering on the topic of using less acids ? and the
properties of the resulting product ?
[Edited on 10-1-2014 by DubaiAmateurRocketry]
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roXefeller
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| Quote: Originally posted by Pard | So can anyone answer me whether a small amount of TATP is applicable for use in caps, like one might use SA,DS or Lead Azide. I'd say HMTD but it's
too reactive with metal.
[Edited on 10-1-2014 by Pard] |
The caps you make are going to be dependent on the base charge you are shooting off. So asking if TATP is good for a cap makes us ask, what is your
application? PETN base charge? What density will you press it to?
[Edited on 11-1-2014 by roXefeller]
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Pard
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Ah sorry, it was PETN as the base. I don't have a technique for measuring the heaviness of the press yet.
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insutama
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petn small synthesis
I was wondering if someone could point me in the right direction for a
synthesis of petn but i only want to make very small amount to try first so if there is a post out there someone could link me to that could help me
out thanks. I have all the chems needed and have read lots and watched lots of vids but i dont like how it was done in the vids and every instructions
i have watched seems a little different so i want to make sure i do this right and have no accidents.
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greenlight
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Searching finds this, someone has asked the same question you have on here before:
http://www.sciencemadness.org/talk/viewthread.php?tid=28405
And full instructions with pictures here:
http://www.powerlabs.org/chemlabs/petn.htm
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Bert
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Threads Merged
14-4-2015 at 18:55 |
Bert
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Please see this old E & W forum post-
http://parazite.nn.fi/roguesci/index.php/t-102-p-21.html
Blaster, where are you now?
| Quote: |
Verified efficient method of preparing PETN from diluted HNO3
use
32,7 ml of 70% HNO3 (75% excess)
18,9 ml of 96% H2SO4
10,0 g of Pentaerythrite
------------------------
or
34,0 ml of 65% HNO3 (66% excess)
24,8 ml of 96% H2SO4
10,0 g of Pentaerythrite
------------------------
or
34,8 ml of 58% HNO3 (48% excess)
36,3 ml of 96% H2SO4
10,0 g of Pentaerythrite
------------------------
Nitration:
1. Cool nitration mixture during mixing of acids, thus minimalize even minimal decomposition of HNO3. Nitration mixture must be cooled before
nitration process to temperature of 10�C.
2. While stiring, add pentaerythritee in small portions (1-2g) to nitration mixture, always after previous batch is dissolved. Nitration mixture
gradually thicken as PETN forming in solution.
3. Constantly monitor reaction temperature and maintain it in 10-15�C range. Interval of adding pentaerytritol conform to reaction temperature, must
not rise over 15�C, leave beaker in cold water.
4. Stir with mixture for next 5 minutes after all pentaerythrite is added and dissolved. Mixture is now thick, but stirring is going well. During
nitration process must not be developed any brown fumes of NOx!
5. Now put beaker with mixture into water bath and maintain temperature at 50�C, continuously stir with mixture. During 20 minutes at this
temperature, all of possible sulfoesters come into PETN for maximal yield of nitration.
6. While maintaining mixture at higher temperature, mixture must be monitored for developing of NOx fumes. Only light brown colour can be in shrouded
beaker. Raised development of NOx pointing to higher temperatures used (even during previous nitration) or insufficient chmemicals purity and further
heating may end up in uncontrolled reaction and oxidation of formed PETN. In this case it is better to do not heat at all and end just after nitration
(if brown fumes apperas during nitration), the yield will be lower. In case of accidentally runaway reaction during heating, immedialtely pour mixture
into cold water, don't try stop reaction by cooling beaker, it will not help.
7. When heating after 20 minutes pass off, pour reaction mixture into cold water and follow standart procedure of filtration, neutralization and
purifying of PETN.
Yield was 22,1g of PETN from 10g of pentaerythrite, ~95% of theoretical yield (with 65% HNO3 used).
This procedure is result of my research of most effective method preparing PETN from diluted HNO3. Acid ratios are precisely calculated on data from
PETN nitration graph published by T. Urbanski in his book vol. IV. Generaly said, PETN is forming to maximum 30% of water portion in nitration
mixture. But, when also H2SO4 is contained in nitration mixture, minimum ammount of water must be keep, or oxidation with small yields occur. With
this acid ratios 20% of H2O is minimum. So, this nitration mixture has 20% of water on nitration start and 30% at the end, area for most effective
nitration, but again only with this ratios. For other acid ratios must be all recalculated. Excess of HNO3 is used to controll ammount of reaction
water. Only ammount of nitration mixture can be extended for lower mixture thickness, but it lower utilization of acids and overall efficiency. But it
isn't necessary.
I hope there is no major mistakes in my translation to english ;-)
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