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shadow31
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[*] posted on 12-12-2012 at 15:42
Question about PETN


Hi i found in this forum this recipe for making PETN posted a couple of years ago by Rosco Bodine

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A tall form 600 ml beaker was secured in a three jaw extension clamp attached to a vertical support rod and clamp holder and lowered into the center of a clear plastic bowl of about 3 liters capacity sitting atop a magnetic stirrer . A stirbar was placed in the beaker , and a thermometer was held in a thermometer clamp was lowered vertically until its tip nearly touched the bottom near the inner wall of the beaker where it would not interfere with the spinning stirbar . The plastic bowl was filled about a third full with ice cubes and a fume intake and exhaust hose was held in a ring near the opening of the beaker . To the beaker was added 100 ml of d 1.5 ( 97% ) pale yellow HNO3 which had been pre-measured in a 100 ml glass stoppered volumetric flask and prechilled in a freezer to -10C . The stirrer was started at a low speed and 1 gram of urea nitrate was added . Additions in small portions of 33 grams total pentaerythritol by sprinkles from a teaspoon were begun , observing the temperature and maintaining the reaction in the range of 18-23C by regulating the rate of addition and adding ice to the bath as needed , siphoning off excess of melt water IIRC was at least once required as it takes a surprising amount of ice for even this small batch nitration . It is a very exothermic nitration and should be carefully watched . The total reaction time was 1 hour from the beginning of the addition to the completion of the nitration . The pentaerythritol appears to first dissolve in the strong acid and then in seconds precipitates as the end product insoluble in the mixture as fine crystals which accumulate steadily , making the mixture thicken more and more as the process continues until towards the end the slurry of PETN is so thick as to be barely stirrable . The temperature range is critical , for at 25C red fumes will appear , but the reaction seems well behaved in the 18-23C range . At the end of the hour the mixture is quickly drowned with ice water , plunging the beaker sideways into its own icewater bath is fine for this , and the PETN filtered , suspended in warm water and neutralized with sodium bicarbonate and a little ammonia and then filtered and dried . The crude PETN was placed in a sealed 1 liter jar with a magnetic stirbar and 375 ml acetone . The loosely capped jar was placed in a hot water bath on the stirrer and heated just to the boiling point of the acetone , cooled slightly below and then unsealed . To the solution of PETN in acetone was added 1 gram of urea and 1 gram of sodium bicarbonate and the mixture capped lightly and stirred for a couple of minutes and then 2 ml of strong ammonia water was added . To the rapidly stirred hot acetone solution was then added in portions small pieces of ice allowing each portion to melt before more was added , total ice about 200 grams , simultaneously with a slow drip 1 drop per second of warm water 250 ml containing about 1% urea as a stabilizer . When all was added the stirrer was stopped and the mixture allowed to stand for a few minutes and filtered . The dried crystals of PETN weighed 73.6 grams , yield 96% of theory based upon pentaerythritol used . The product is a snow white , colorless and odorless , reflective free flowing crystalline material which very much resembles table sugar and is very temperature and storage stable , and has desirable handling and loading properties . The product was dust free and appeared very consistent in particle size although it was not screened . It was good for use and lumpfree straight from the drying on the filter , the sort of material where one simply folds the filter and pours the dried material directly into the storage bottle , and there is little to no residue left sticking to the paper . Ah yes , the good stuff :D

Although it looks pretty good to me i am not sure will this recipe produce a high quality PETN ?
and two more questions, will it affect the quality of PETN if i skip the usage of urea, and what exactly is d 1.5 ( 97% ) pale yellow HNO3, i have a pure (98%+) nitric acid how to make that one ?
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Swede
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[*] posted on 12-12-2012 at 16:57


It's not a recipe.

Urea is for stabilization, to act as a scavenger for acidic byproducts and decay compounds.

I'd recommend you not pursue this. Start with hobby pyrotechnics instead, learn a bit about chemistry.
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shadow31
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[*] posted on 12-12-2012 at 23:51


Sorry, but i find this substance perfect to start with, considering power/ease to do, besides i dont have the money for reagents to start with simple substances, i know a bit of chemistry well just a bit so i will be happy if you help me, and i already made a remote detonator and blasting caps so a good explosive is now all i need

PS: i am not a terrorist or anything this is just some kind of new hobby for me
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virgilius1979
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[*] posted on 13-12-2012 at 05:14


I've done a few nitrations and this is not the easiest, nor the most difficult (like RDX synt. for example). I've got runnaway reactions 2 times. So please take care to do it outside or in a fume hood, with proper stirring and cooling. Start with small quantities and don't hurry adding the reagents.
I agree with Swede, that pyrotechnics are much easier to work with (nevertheless still dangerous) and not difficult to aquire (at least for me it's easier to get Al and oxidisers than 98% nitric and sulfuric acids).
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shadow31
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[*] posted on 13-12-2012 at 06:48


Quote: Originally posted by virgilius1979  
I've done a few nitrations and this is not the easiest, nor the most difficult (like RDX synt. for example). I've got runnaway reactions 2 times. So please take care to do it outside or in a fume hood, with proper stirring and cooling. Start with small quantities and don't hurry adding the reagents.
I agree with Swede, that pyrotechnics are much easier to work with (nevertheless still dangerous) and not difficult to aquire (at least for me it's easier to get Al and oxidisers than 98% nitric and sulfuric acids).

I will take all the safety measures, so about that urea nitrate and the urea at all will it give a higher detonation velocity or it is just for stabilizer, and those 375g acetone once i used it can i use it again ?

Sorry for my bad english

[Edited on 13-12-2012 by shadow31]

[Edited on 13-12-2012 by shadow31]
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virgilius1979
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[*] posted on 13-12-2012 at 11:03


Urea is just a stabilizer, it doesn't increase detonation velocity.
You can recycle the acetone.

Quote: "Although it looks pretty good to me i am not sure will this recipe produce a high quality PETN ?"
Rosco Bodine is a very experienced and respected member of this forum. I myself have reproduced some of the protocols he provided, and all of them worked very well. This doesn't mean you cannot try to tweak some steps of the reaction, although, for the first time I'd try to reproduce some tested working protocol.
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[*] posted on 13-12-2012 at 13:51


Ok, thank you, can you give some tips how to make a stirrer for a magnetic stirrer, because i will have problem with some acids, if i put a simple iron for stirrer, and that acetone to reuse it i need to distillate it right ?

[Edited on 13-12-2012 by shadow31]
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virgilius1979
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[*] posted on 14-12-2012 at 07:10


That acetone could still contain some PETN disolved so take care about distillation, perhaps better to put the flask in a water bath. Although if you want to reuse the acetone for another round of PETN, you could use it as is.
About the magnetic stirrer, I made one using a fan to which I have removed the blades and sticked some small neodinium magnets on top, than fixed it in a small case with a plastic lid on top, and it works just fine with magnetic bars (you need to buy one, they are covered in teflon which resists the acids).
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[*] posted on 15-12-2012 at 07:40


It is possible to make a stirrer bar by inserting an iron bar or wire into a fitting glass tube and then melting the ends closed. Not really worth the trouble (they are cheap and easy to find on ebay) unless you want to do some micro scale chemistry and need an extra small stirrer bar.
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shadow31
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[*] posted on 15-12-2012 at 08:22


Well i'll just buy one melting the glass will be problematic, and how unstable will petn be without urea ?
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[*] posted on 15-12-2012 at 09:22


All nitrated esters, unless meticulously washed, neutralized, and preferably stabilized, will degrade. It's not a matter of if, but when.

Urea is ubiquitous. It is a major component of many fertilizers. It can be bought by the kilogram cheaply. No reason not to make use of it.
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[*] posted on 15-12-2012 at 13:28


Quote: Originally posted by Swede  
All nitrated esters, unless meticulously washed, neutralized, and preferably stabilized, will degrade. It's not a matter of if, but when.

Urea is ubiquitous. It is a major component of many fertilizers. It can be bought by the kilogram cheaply. No reason not to make use of it.

Then i;ll take it probably in Monday i'll go to the chemical store and will take all at once, i dont know how it is in USA or where you live but here i can buy all kind of reagents that are available for universities and schools so at least this is not a problem

[Edited on 15-12-2012 by shadow31]
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[*] posted on 15-12-2012 at 18:01


i use 5kg of 98% nitric acid for 1kg of pentaerythritol at 40c.. yield about 2.2 kg..
in 1 hour i can do that..
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[*] posted on 15-11-2015 at 23:31


Sorry for restarting such an old thread but I have a few questions regarding synthesis of PETN.

First I found a synth that requires little equipment on the xfactorchem channel (you tube) yeah I know not the most reliable source of info. Do you think this guy knows what he's doing and that this is a safe synth?

Second this is my first attempt at nitrating anything. I have read much on the matter but there is little info outside if this very knowledgeable community any tips or personal experiences/ mistakes?

His synth calls for 65% HNO3 could I use 67 to 68% and get away with not changing anything else?

How long would this store for in an air tight container away from light?
If you don't know would it still be usable after a year?
If this decomposes in storage is it a safe one or an energetic one?

Finally how safe would this be if you were to use safe decomp and low sensitivity to hot climates and being treated roughly eg being dropped and shaken in its container as being a very good level of safety.

Sorry if I asked any stupid questions I'm pretty shure about most of them just want to check my info is correct before I actually do anything.
Thank you in advance.




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[*] posted on 16-11-2015 at 01:24


That video seems correct except for the fast addition of the pentaerythritol which will lead to a run-away. The yellow/brown colour of the mix in the beaker in the video is an obvious sign of the onset of a run-away reaction as mine always stays white during the addition and the one time I got a slight yellow colour, the mix had to be dumped a minute later.

I have used 65 and 70% Nitric acid while keeping the Sulphuric acid amount the same and no change in yield was noticed.

If the PETN is properly washed, recrystallized and acid-free, then yes you can store it for a year in an airtight container like you say and yes it would be just as useable after a year. It should not decompose if it is acid-free. I don't think a hot climate would be a problem as it remains stable even at high temperatures.
As for the rough treatment question, even though it is a secondary, you would be extremely careful not to handle it roughly.

COPAE states that PETN is the most stable and least reactive of the explosive nitric esters and shows no trace of decomposition when stored at 100 Degrees Celcius for a long time. It is detonated from a 20cm of a 2 kg weight in the drop test.

You seem to be unsure of the explosive and handling properties of the compound. I think you should read some more before you attempt the actual synthesis.




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[*] posted on 16-11-2015 at 01:43


The reason I questioned its handling properties is because I have read many sources saying its safe enough to handle without to much care and then read one source that claimed it quite sensitive eg hammer and fuse which I believed to be wrong.

It is this reason I wanted to check because fingers are worth more than a little extra time to inquire as to safety.

Thank you for your time to reply I appreciate it very much
PS don't worry I would never treat any explosive like that I always treat everything as though it could go off at any moment safety is always my number one concern.




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[*] posted on 16-11-2015 at 08:01


Ah i see now, no a fuse is not going to cause it to detonate, if you take a small sample and ignite it, it will melt and burn on it's own. A large amount could possibly achieve DDT and detonate if you ignited it depending on amount/purity/temperature it is subjected to/etc.

Here are the properties for PETN from the book Introduction To The Technology Of explosives by Paul Cooper and Chemistry Of Powder & Explosives by Davis that should help:

Drop test= 17 - 20cm @ 2 kg weight
Friction pendulum= Steel shoe = crackles - Fiber shoe = unaffected
Rifle bullet impact test= Exploded 100% with .30 calibre at 30 yards
Temperature to cause explosion= 210 - 272 Degrees C
Min amount lead azide to cause detonation= 0.01 g

PETN does not take fire from the spit of a fuse. It is relatively insensitive to friction only crackles when rubbed in a mortar and pestle. Very sensitive to initiation from primary explosives.











[Edited on 16-11-2015 by greenlight]




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[*] posted on 16-11-2015 at 11:18


One more question is PETN compatable with DDNP like as in will they react in a blasting cap if touching?



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[*] posted on 16-11-2015 at 20:22


Yes, you can make a detonator using PETN as the base charge and DDNP as the primary initiating charge.



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[*] posted on 9-12-2015 at 19:45
More blasting cap fun


Here I am again looking for help with det caps.
What can I say I want a perfect balance of safety storability and simplicity.

Now I have studied SADS in theory but a piece of paper and personal experience are two different things. Hence me coming here.
The first question I have is assuming my usual cap is either 8gm Ap or 6gm DDNP how much silver double salts do I need to equal this I'm having doubts about its effectiveness based on the low gas out put on det.

Will this stunt its ability in detonating AN mixtures particularly ANAl?

Also what is its sensitivity like if compared to AP HMTD and DDNP as these are the primarys I am familiar with handling. Again I have read the data sheet but a number on a data sheet means nothing to me if I dont have experience handling somthing of close sensitivity.

Finally from what I have read it is chemically stable will it likely detonate in storage without outside stimulation?
And assuming air tight out of light storage conditions(because most silver salts are sensitive to this) how long could this be stored for in a mild climate?

If all this checks out my cap will be Al tubing 5 grams PETN and 2 grams SA/DS.
Assuming that quantity will detonate PETN if not out comes his little brother ETN. Sorry if this appears in the wrong thread just thought it belonged with my previous post if not the mods will growl me.

Mabey I should start a thread were every one shares there various cap combos and asks advice.




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[*] posted on 9-12-2015 at 23:46


Even 1 gram of SADS will easily detonate hand pressed pressed PETN in an aluminum 7-8mm ID tube.
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[*] posted on 10-12-2015 at 13:05


Dial down the quantities by an order of magnitude...

E.g. like this train:

Safety fuse->80mg sads carrier->50-80mg loose secondary->0,5g pressed secondary charge
DSCF0986.JPG - 825kB

Joined without applying strong forces to create a rather reliable compound:
DSCF0984.JPG - 457kB

As for storage stability in my experience has been almost a year without degradation or loss functionality. But that is just my personal experience with pure and recristallised components. And it is better to keep the primary and secondary carrier components stored separately. Combine just before use.




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[*] posted on 10-12-2015 at 15:27


Nice cap!! Thanks for awnsering my questions I have just one more which is about cap pressing set ups.

I think most if us have seen the YouTube video if the guy with the arbor press setting the tourqe wrench to 74lbs and proceeding to press caps at 3000psi how does that work is there an equation I can use to get how much force I'm putting on caps with a given set up is it somthing to do with the surface area the force is being asserted on?
I was thinking of modifying a bench vice or similar for this with a blast sheild and such.

[Edited on 10-12-2015 by Dark Alchemist]




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[*] posted on 10-12-2015 at 21:48


Quote: Originally posted by Dark Alchemist  
Nice cap!! Thanks for awnsering my questions I have just one more which is about cap pressing set ups.

I think most if us have seen the YouTube video if the guy with the arbor press setting the tourqe wrench to 74lbs and proceeding to press caps at 3000psi how does that work is there an equation I can use to get how much force I'm putting on caps with a given set up is it somthing to do with the surface area the force is being asserted on?
I was thinking of modifying a bench vice or similar for this with a blast sheild and such.

[Edited on 10-12-2015 by Dark Alchemist]




For the 3000psi, I suspect he knew the circular area of his detonator casing. After that:

Torque = force * arm-length
pressure = force/area

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[*] posted on 10-12-2015 at 22:50


Thank you to all I very much appreciate your cooperation.

I think you have awnsered all my questions for the now and not only have I learned more here in 48 hours than google could teach in several weeks but you have all gone about it in such a professional manner that wouldn't normally be expected from a forum.

The way I see it least I can do is put that info to good use and so will probably be absent for several week's
once I have returned i will have a little more experience all thanks to you guys.

Once again thank you.
my thirst for knowledge has been quenched though I shall soon again be thirsty.

Dark Alchemist S.O




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