Accident in the making?

[spydamonkee]

on meglomania's synthesis page of <a href="http://roguesci.org/megalomania/explo/acetoneperoxide.html" target="_blank">CTAP</a> this is written @ the bottom:

"Mixing with RDX, PETN, or picric acid will improve the stability of this explosive. "

now my chemical knowledge is no where near that of some forum users especially meglo... but i know the importance of washing CTAP after production so the acid does not continue to react making the AP extreamly unstable. also i read so often about how other acids should not be introduced to CTAP incase it sensitizes it enough to just 'go off', yet meglo is saying to use mix CTAP with Picric Acid to improve the stability
I was wondering weather you could clarify this meglomania...
is it dangerous for CTAP to be mixed with acids after production or is picric acid an exception?

not to mis trust your judgement or anything just thort i owuld get this clarifyed just incase it cost someone fingers' hand' arm etc

[Anthony]

EEK! <img border="0" title="" alt="[Eek!]" src="eek.gif" />

Looks like one of those late-night, slip of the mind errors!

[NERV]

I think this might be true I remember seeing something in the archives on this. I have to go find it again, but from what I can remember form the topic they used 50/50 mix. It was supposedly stable. Correct me if I am wrong though I am just going off memory.

[Kalium]

Excuse me if my english is so bad.

At first, picric acid is very weak acid. At all, only H2SO4 have very bad influence on AP (it incresease dipolymerisation of TCAP). (but it doesn't mean that you shouldn't wash AP if you prepearing it with other acids).
In one french patent I read, that picric acid should be mixed with AP by flowing its alcohol solution.

[Boob Raider]

Anyways Picric acid is not even a true acid (meaning it doesn't turn blue litmus red) same as phenol (carbolic acid). The only reason I think it is classified as an acid is because it forms salts. I have had this mixture but the CTAP tends to vaporize in about a week, so I have had no luck storing it although it does make CTAP little bit insensitive to shock but, it is still heat sensitive. The decomposition might be due not properly washed picric acid with traces of mineral acids.

[Madog555]

i am willing to say that you could probaly mix AP with very pure TNP. BUT, our TNP has a high amount of H2SO4 present from the process used to make it. it is very hard to rid it of all the H2SO4. so, i bet megas page is correct but i wouldnt do it espwcialy with the homeade stuff.

[kingspaz]

can we please stick to just the plain AP abbreviation when refering to acetone peroxide. theres no need for anything else.

[megalomania]

Indeed acetone peroxide, or AP for The Forum, is more the more appropriate name as it is commonly a mixture of tricyclo, dicyclo, and other polymeric materials. I have recently updated my website to reflect this, as well as a reaction scheme that shows how acetone peroxide, or ketone peroxides in general, are formed. The names on my website are all those that have appeared in published literature, I have never seen CTAP. Also remember that AP is only used on The Forum, in the literature it means Ammonium Picrate, not to be confusing :)

The bit about mixing AP with those other explosives is a direct quote from a literature source. I am not sure whether it was from the original developers of the stuff, or whether it was from a reference to the early military tests of the substance quoted in The Encyclopedia of Explosives and Related Items Vol. 1. Regardless, I trust the source.

Indeed picric acid is not in not like the other acids as its pKa is relitively high (rather this is a chemical technicality due to the acidic proton of the alcohol, in this same way phenol is acidic). However, do remember that you should not keep primary explosives sitting around for too long, and that picric acid still has some acidic properties. I would not advise keeping such a mix for years on end. This is exactly why the military determined AP was unsuitable for their needs.

[simply RED]

I couldn't understand the process of CTAP synthesys again, is oxigen liberated or it's not?
it must be, when HOO-CR2-OO-CR2-OO-CR2-OOH becomes cyclic, O atom must be liberated, what happens with that O atom , does it peroxidizes a molecule of ketone or it catcehs another O and goes away from the reaction mix
O + O =O2

[andreas]

Mega onother thing I noticed on you're website is that you state HMTD was used in detonators. By that did you mean by the militarie or by Forumites

[Hex]

I guess that the oxygen from acetone will be liberated eventually as water. It probably proceeds through attack at the O-protonated carbonyl site of acetone by H2O2 oxygen (which will be a fairly good alpha effect nucleophile) to give, after deprotonation at the peroxide oxygen, CH3-C(OH)(OOH)CH3, which is going to be very unstable. After this, a few things could happen; protonation at the OH and attack by another H2O2 to give CH3-C(OOH)2CH3 or possibly (less likely) elimination of OH- to give [CH3-(C=O-OH)-CH3]+ which would react with a further H2O2 to also give CH3-C(OOH)2CH3. Carry on the reaction using fragments like these in the place of H2O2 and eventually you'll get ring assembly. All these reactions are probably reversible, but luckily enough the fully cyclised products fall out so we get what we want eventually.
ps - I have to take issue with the idea that picric acid "isn't really an acid" - it's not mineral acid strength, but it'll certainly displace CO2 from carbonates etc and will react with metals - which is why it's not a good idea to put picric in aluminium tubes.

<small>[ September 11, 2002, 10:05 AM: Message edited by: Hex ]</small>

[kingspaz]

also, mega i'd like to point out that your structural formula for HMTD is wrong as you are missing the O-O peroxide bond.

[megalomania]

I did indeed err in my graphic, two dashes instead of an O in there. The updated one will appear in my next update.

The use of HMTD in detonators was a long time ago, probably European military or civil war era IIRC.

[spydamonkee]

you would think AP would be preferred in detonators instead of HMTD as the latter aint very compatable with metals.

well all my BC's are AP :D

[Madog555]

AP sublimates. and it can do it even if in a tight container. it can sublimated and recrystalise amoung itself. HMTD was chose over AP because HMTD can be stored for periods of time. i wouldnt store it for realy long though. HMTD is also more powerful than AP

[Marvin]

Phenol and picric acid look like alcohols, but this is deceptive. The benzene ring the OH is attached to is electron withdrawing and resonance stabilising. The result of this is to make a feeble acid of pka just under 10, out of what would be an alcohol of pka 18. This may not seem impressive, but its a big jump in organic terms. Phenol wont displace carbonate, and titrations have to be done with phenolpthalein against sodium hydroxide, which it will neutralise but this is where things get more interesting. The nitro group is electron withdrawing, resonance stabilising and picric acid has 3 of them. The result of this is to turn the feeble pka of phenol into the strongest organic acid most chemists will ever use. With a pka of 0.38 its stronger than most inorganic acids, though its completely outclassed by sulphuric, nitric etc, so is everything else.

Theres nothing special about the COOH acids, its the electron withdrawing effect of the =O and the resonance of the ion that make the C-O-H part acidic. Acetic acid pka is 4.76. Remeber these are log scales, so a small difference in pka has a massive influence chemically.

For more detail, check a good uni organic chem book. Solomans "Organic chemistry" 5th Ed, p942 is a good reference.
CRC handbook has a fairly long list of organic acid constants.

On the subject of Acetone Peroxide, it seems to sublime much more readily than it actually decomposes, making any sort of mixture that prevents this has the apearence of making the compound much more stable chemically. Hydrogen peroxide is most stable when slightly acid. Maybe this is another effect. Ive never stored AP for any lenth of time and I never plan to. I was shocked the first time I made it at how fast it disappeared from an open sheet of paper. Virtually gone in 3 days. As for detonators, HMTD might be unstable with metal salts, I would expect AP to be the same if not worse. Furthur more properly purified HMTD is chemically stable at room temp (extrapolation from the results in Davis), AP is not.

Stay safe.

[NoltaiR]

Only in some high explosive literature does AP refer to ammonium picrate; if you happen to be reading about something to do with experimental rocketry (or just rocketry in general), AP will most likely refer to ammonium perchlorate.