From: AHAHMA%kontu.utu.fi@ssyx.ucsc.edu
Subject: Peroxides
Date: 6 Mar 90 18:14:25 GMT

>     Any answers to the questions posed above or any other interesting
>info about H2O2 would be greatly appreciated.

Concentration by distillation should be carried out under vacuum to prevent 
decomposition of the peroxide. As the concentration approaches 70 % and over
there will be a considerable risk of an explosion. Further, you would need 
a fractionating apparatus to get some yield. The apparatus must be extremely 
clean, even traces of metallic impurities may cause hydrogen peroxide to 
decompose violently.(Cu,Co,Ni,Fe,Mn at least)

The peroxide is quite difficult to detonate, unless it is over 85 % and/or
hot, like during distillation. But, detonating such high concentrated
peroxide would be just a waste of a good raw material. A better idea is to 
make some organic peroxide of it. Besides, you will need only 30 % H2O2 to make
for example acetone peroxide.

Acetone peroxide is very sensitive to shock, friction and especially sparks and
flame. It must be handled with great care and it MUST NOT be stored more than a
few days. 
Right after preparation it contains considerable amounts of water (20 to 
30 % by weight), that makes it more insensitive and it is possible to handle 
it. However, it loses this probably occluded water gradually and becomes 
extremely sensitive, even more sensitive than mercury fulminate. If the 
peroxide is dry, it always explodes with a great violence regardless of 
confinement. Also, it sublimes at 56 C and slowly crystallizes inside
a closed vessel at room temperature. These crystals are dangerous to even 
touch. They adhere very tight on the walls of the vessel and if you try to 
scratch them off, they don't like it at all. One crystal is very capable of 
igniting the whole amount in the container. This is also why you must not put 
this peroxide in screw-cap containers, there may be crystals between there. 
Guess what happens, if you then screw the cap!

Right after preparation (air dry, dried at ROOM TEMPERATURE) it burns with a 
great flash, a teaspoonful makes a fire ball of about 0.5 meters in diameter, 
if lit unconfined. It looks quite spectacular, just like car explosions in the 
movies. I actually call this peroxide a movie explosive, since the flash makes 
only a slight and deep boom. Even the flame created won't burn anything. 

NOTE: If the peroxide is under a slightest cover, for example inside aluminum 
foil, it will always detonate on ignition, even if it contains some water.

There are also many other organic peroxides, that are similar to acetone 
peroxide. To mention some I've tried: cyclohexanone, methylethylketone, 
cyclopentanone peroxides and HMTD. HMTD can be made directly with 3 % hydrogen 
peroxide, but the yield is low and the product crystallizes in big crystals, 
that are dangerous.

3P

Newsgroups: alt.engr.explosives
From: wfvisser <wfvisser@dds.nl>
Subject: Re: acetone,hydrogen peroxide and HCl
Date: Wed, 7 Feb 1996 00:02:30 GMT

Tomyv wrote:
 
> Other than being extremely explosive, does anybody know what this is?
> please reply

In short:
extremely sensitive, and not suitable for 'experimenting'.

To be more specific:

You are referring to the white crystalline product that forms when
acetone (2-propanone), hydrogen peroxide and a mineral acid (I prefer
H2SO4, since HCl tends to increase the rate of decomposition of the
product) react. The product is a mixture of 2 compounds. I do not have
their IUPAC name's at hand, but they are both cyclic compounds. They
are the dimere and trimere (mainly trimere) of the following compound
(which in pure form is a colorless explosive oil, formed by the
reaction of hydrogen peroxide with acetone under neutral circumstances):

      OH
     /
 Me2C
     \
      OOH

The cyclic tetramere and higher do not form because of ring strain
(they are too strained to exist).

The explosive mixture of the dimere and trimere is very, very sensitive
to both friction and shock (Shock sensitivity: 0.3Nm, friction
sensitivity:0.1Nm) It also tends to sublime quickly at room temp. This
may cause crystals to form at the screw cap of a container, so never
use screw caps (You should not store this anyway). It also decomposes
at room temp.. It's half-life is about 4 months. Trace amounts of HCl
left seem to catalyse the decomposition. In the days I used to make
this, I used H2SO4 for that reason. Rinse the crystals with ammonia to
neutralize any acid left, and then thouroughly wash any remaining
ammonia/ammonia salts etc. with water. Wash at least 6 times. Prepare
only very small batches and do never store this compound.  The
explosive is not suitable for commercial use (and even less suitable
for any other use), because of its sublimation and decomposition.
Besides, most explosives perform better than this one and are much less
sensitive.

Wouter Visser.

Subject: Re: chemistry questions
From: arno@utu.fi (Arno Hahma) 
Date: Jun 25 1995
Newsgroups: rec.pyrotechnics

In article <3skhj8$efm@news.ccit.arizona.edu>,
Tom Perigrin <tip@lead.tmc.edu> wrote:

>Acetone peroxide - too darned dangerous to fool with.   The only thing that

Fortunately, it is not so dangerous to make. Freshly prepared acetone
peroxide contains fairly large amounts (20..35 % by weight) of crystal
or occluded water, that desensitizes the material a lot. The "moist"
peroxide burns with a large fireball, if ignited in the open and in
relatively small amounts. It will explode only, it it is confined or
ignited in large piles (more than 50 grams or so).

If the water is removed, then the peroxide is _really_ touchy and
always explodes when ignited. The water is lost slowly, if the material
is kept for prolonged time. Therefore, the peroxide becomes more
sensitive over time. That is a dangerous property, as one might think
"it wasn't so bad when it was made" and then treat it accordingly.

>has never been used commerically, because it is too senstive. 

and because it is highly volatile. 

ArNO
    2

Subject: Re: How concentrate 30 % H2O2 to 90 % H2O2
From: nreitzel@lonestar.jpl.utsa.edu (Norman L. Reitzel   )
Date: Feb 29 1996
Newsgroups: sci.chem

In article <31330953.0@news-feed.tfi.be> P. COCKS <> writes:
>Is it possible with a litle chem lab to concentrate
>H2O2? 
>What are the dangers of 90 % H2O2 ?
>Can it explode spontanously ?

You can concentrate 30% H2O2 to 90% by drying it in a dessicator over 
concentrated sulfuric acid.  Use a 4:1 ratio of acid to peroxide.

The 90% peroxide is -quite- explosive unless it is -absolutely- pure.  
Worse, it sets things on fire on contact.  If you plan on doing this 
thing, go to a Library first, and read the article on hydrogen peroxide 
in _Preperative Inorganic Chemistry_.


-- 
   Norman L. Reitzel, Jr.       |    "When you live beside the graveyard,
   nreitzel@lonestar.utsa.edu   |     you can't cry for every funeral."
   Blue Water Ventures, dba.    |                     Russian Proverb

From: gherbert@crl3.crl.com (George Herbert)
Newsgroups: alt.engr.explosives
Subject: Re: Concentrating Peroxide.
Date: 30 Jul 1999 17:05:37 -0700

Social d84 <sociald84@aol.com> wrote:
>>3 percent hydrogen peroxide can be concentrated by boiling it in a glass or
>>enameled pan (medium boil).  Make sure every thing is clean and dust free
>>to pevent decomposition of peroxide.
>
>are you sure of this? I have heard that peroxide boils at a lower temperature
>than water, but it freezes at a lower temperature.

MP -0.41 C; BP 150.2 C.

However, it is recommended that you not concentrate it via heating,
as if you succeed it may spontaneously decompose.  The low grade
H2O2 is usually not pure enough to be concentrated safely, and making
hot concentrated peroxide magnifies the decomposition risk due to
any present impurities or due to surface action with the container.
The usual concentration method is fractional freezing which gets
you to 59% if I recall, and then the remaining mix freezes all
at the same rate and can't be further concentrated.


-george william herbert
gherbert@crl.com

From: ems@michael.apple.com (E. Michael Smith)
Newsgroups: rec.pyrotechnics
Subject: Re: H2O2
Message-ID: <1993Jan22.212927.13891@michael.apple.com>
Date: 22 Jan 93 21:29:27 GMT

In article <1993Jan21.220757.16035@cs.rochester.edu> dietz@cs.rochester.edu (Paul Dietz) writes:
>In article <1993Jan21.152605.22932@ux1.cts.eiu.edu> cfthb@ux1.cts.eiu.edu (Howard Black) writes:
>
>>> Hydrogen peroxide boils at 150 C, so you can concentrate it by
>>> distillation (probably under a partial vacuum).
>
>>    You can also kill yourself doing this.
>
>I thought that went without saying in this group.  Oh well.
>
>Hot hydrogen peroxide can experience runaway decomposition or
>detonation, but I was thinking of vacuum distillation.  I have in
>front of me the following quote from Sarner, "Propellant Chemistry":
>
>  "Hydrogen peroxide of 98-100% is immune to mechanical impact such as
>  drop-weight or rifle-fire tests, and it does not appear possible to set up a
>  self-propagating detonation through the action of blasting caps.  Definite
>  explosive effects have been noted only under the influence of powerful
>  booster charges combined with a high degree of confinement."

I'm amazed that this is in print.  I've met a guy who was short
two hands due to a H2O2 detonation.  He was working in a chemistry
lab in the UC system and was carrying {either a tray with
bottles on it, or one bottle in each hand} concentrated H2O2.
It went off of its own accord and he got two steel hooks.

It may not be reliably detonated, but it also cannot be reliably
NOT detonated...


--

E. Michael Smith  ems@apple.COM

'Whatever you can do, or dream you can, begin it.  Boldness has
 genius, power and magic in it.'  -  Goethe

I am not responsible nor is anyone else.  Everything is disclaimed.