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.