Sciencemadness Discussion Board

Thermobaric Composition

ChemichaelRXN - 27-9-2020 at 03:08

I am an innovator and part of my product idea uses the thermite I am going to speak about, but have you ever added wax pellets? I dont make anything explosive or I definitely wouldn’t post this, but I know a little about this thermobaric material.

Apparently the mixture of Copper Oxide and German black aluminum (you need the carbon for quicker ignition) with wax pellets or other combustible dense pellets (maybe plastic) is what makes up thermobaric explosives. I thought I’d share because I found it interesting. Copper oxide blasts with a lot of heat quickly so I can see how adding something combustible adds a wave of dense heat.

Thermite reaction:

3 CuO + 2 Al —-> 3 Cu + 1 Al2O3

When this mixture explodes does it have an even higher m/s blast because of the wax added? Maybe someone that knows about this mixture can provide more info.


Tsjerk - 27-9-2020 at 06:11

Do you have a source for German black aluminium containing carbon? I can only find people on pyro forums claiming it does. I was under the impression CuO/Al is fuse sensitive because of the particle size.

Did you compare the thermite with and without wax? In this mixture CuO is the oxidizer, I don't see CuO/wax being a very energetic mix. Why do you think it would perform better with wax added?

I wouldn't be surprised if the wax it only there as a binder.

Herr Haber - 27-9-2020 at 07:26

I highly doubt it'll have any practical effect in that regard.
Cu thermite is "explosive" partly because of the BP of copper / partly because of all the air between the particles that gets superheated.
Air is replaced by wax, air is not heated, wax MELTS, takes away heat and burns though certainly not hot enough to keep the reaction going and you're done.

Might be wrong but this is what I imagine would happen.

ChemichaelRXN - 27-9-2020 at 07:50

I haven’t tried it with wax or plastic beads (just the thermite alone in the past), but I was thinking that the copper oxide thermite would explode and then the wax pellets would burn and have a heat wave clap to it. (Thermobaric) The wax isnt part of the single displacement reaction.

unionised - 27-9-2020 at 07:56

Quote: Originally posted by Mr.StinkyGas  
but I know a little about this thermobaric material.

Very little.
It's not thermobaric.
Even wiki would tell you that "A thermobaric weapon, aerosol bomb, or vacuum bomb is a type of explosive that uses oxygen from the surrounding air to generate a high-temperature explosion."

ChemichaelRXN - 27-9-2020 at 08:18

Anyway, I do know very little, I dont make anything explosive, just thought I’d share an interesting topic. I did research in the past which I cant find any longer online that said they used copper oxide thermite with plastic pellets. It was a chart/list... That is what may have been used in the FOAB. (There was a list of weapons with compositions and I could have sworn I seen copper oxide thermite listed as part of the composition)

ChemichaelRXN - 27-9-2020 at 08:31

It also does use oxygen from outside of the quick single displacement reaction to burn the wax/plastic pellets.

Pellets of tungsten oxide thermite added would be interesting to see as well as it has the highest melting point out of all elements. Copper’s melting point is 1085C and tungsten is 3422C.
Anyway, I find it interesting to talk about and that is how far it goes. I feel it would work.

Antiswat - 8-10-2020 at 07:40

true thermobaric is where you have an explosive fuel-air mixture which then is initiated by a shockwave, one guy on youtube pulled it off first setting off a charge dispersing gasoline, and then 3 metres away iirc with maybe 100ms delay a second charge went off, the idea is that the shockwave causes the gas air mix to detonate at close to same speed as the shockwave hitting it, while gas air explosions are typically much slower

thermobaric is term sometimes used just to explain explosion with excessive fuel, i believe this is what chemichael is trying to accomplish, i see the light in this idea, maybe you could get more knock out of it if you used magnalium or magnesium instead of aluminium, you can also get hydrogenated castor oil, something is telling me that stuff would be better choice for this effect

ChemichaelRXN - 8-10-2020 at 13:03

Thanks for the great information to provide better clarity. (I wont try it out due to legal reasons, but I made thermite before, so I was wondering)

foreign maple - 26-10-2020 at 16:20

wax is commonly added to energetic materials to increase the stability and density of the composition.

The majority Phlegmatized compositions contain ≈ 5% paraffin wax but in some instances this may differ. paraffin wax is not the only agent that is used but it is quite common, it is used in RDX, Octyl and Pentolite. I would recommend using a smaller amount if you are planning to make a thermobaric comp though.

Fyndium - 30-10-2020 at 00:49

Quote: Originally posted by Tsjerk  
Do you have a source for German black aluminium containing carbon? I can only find people on pyro forums claiming it does. I was under the impression CuO/Al is fuse sensitive because of the particle size.

Only source that I have seen is that carbon/graphite powder is used in milling to prevent oxidation of aluminum powder.