To what extent is CuO an oxidizer in organic compositions?

[Potassiumchlorate]

CuO with an organic fuel will not burn. With copper it will make very powerful thermite, though.

 

What about CuO in compositions with chlorates and perchlorates? Does it work as an oxidizer to some extent?

 

The idea that it does struck me due to the fact that Pihko AP#1 has less than 60% AP. The main fuel is sulfur. A few percents of red gum is added (I guess) to speed the burning up and elevate the temperature a bit.

 

Your opinions?

[WSM]

I would say in an organic composition, CuO contributes nothing as an oxidizer, but is mainly a color donor and a burn rate catalyst.

 

WSM

Edited January 30, 2013 by WSM

[Potassiumchlorate]

Speaking of catalytic properties: copper oxyhloride seems to be more of a catalyst than copper(II)oxide. Everything else the same, a composition with oxychloride burns faster than one with copper(II)oxide, although copper(II)oxide has other benefits, like higher copper content.

[Zumber]

red gum is primarily an organic fuel in fireworks its use as a binder is much less common,as you mentioned CuO with organic fuel wont burn so my guess is AP and red gum is a base mixture and CuO acts as a colouring agent and sulphur plays a role of catalyst+fuel.

[Mumbles]

I guarantee sulfur is not a catalyst. Also, do be aware that you can just look up the composition. He did give the name of the formula. No guessing of base mixture or usage required.

[Seymour]

I am pretty confident that CuO fully liberates it's oxygen in organic compositions and if you were going to be perfectionist you should consider this in balancing reactions. It's sluggish and relatively low in oxygen, so many people get away with thinking it's inert, but in the context of a perchlorate or chlorate and resin flame it will be anything but inert.

 

Has anyone else seen or done the reaction of CuO and charcoal? At high school we heated the mixture in a test tube until activation energy was reached. There was a dull flash of light, and in a puff of CO/CO2 metallic copper was sprayed all over the inside of the test tube and out the end.

[Potassiumchlorate]

Oh, I see now that I should have written "with aluminium it's a very powerful thermite"

 

Yes, Seymour, that's what's I've been thinking too. Theoretically CuO would react with shellac in a ratio 92:8. Outside a testtube it certainly doesn't. But with help from other powerful oxidizers, that do react with shellac on their own, it should.

Edited January 31, 2013 by Potassiumchlorate

[Mumbles]

I have no doubt that it liberated it's oxygen somehow. The fact that you're seeing blue is proof of that. The other color emitting species of copper can be green and red. I don't recall exactly what color CuOH makes, but it's in Hardt. To me it's more of a question of if the oxygen is truly oxidizing something, or just being replaced.

 

Something akin to:

 

CuO + 2 HCl ---> CuCl2 + H2O (no oxidation, but it's being replaced)

CuO + CO ---> Cu + CO2 (oxidation)

 

I chose the oxidation reaction specifically by the way. I really don't think that copper oxide is going to be reacting directly with any organic fuels the way it might with a metal or straight charcoal. It may be sort of "sacraficially" reduced later on though.

[AirCowPeacock]

But doesn't AP decomp forming Cl, not HCl?

[Mumbles]

Flame chemistry is far from an exact science. I honestly don't know where to check or make any confirmations on this, but I've been under the impression that ammonium perchlorate is more prone to making HCl than Cl2 compared to other oxidizers or chlorine donors. Both HCl and Cl2 are efficient chlorine donors in a flame environment, and more than likely, neither actually exist as written here. I don't know if there is a complicated mechanism for this, but there is a very good reason that indoor pyro has to be extremely carefully formulated. I know I've gotten little whiffs of HCl when testing AP comps.

 

AP alone, you can make a good equation to go to chlorine gas. In a flame environment, who knows.

 

I was just trying to say that the copper is getting a chlorine atom somehow. There are more than one way to do that.

[psyco_1322]

I'd agree with the theory of it most likely going to HCl. At PGI when we set off AP based salutes, you can smell the HCl in the smoke, and also on the debris from the salute, if you can find any It's pretty distinct, not anything like that of your common KP/Al stuff.

[schroedinger]

Be sure, CuO will work in as an oxidizer with organic components, but it needs quite high temperatures to ignite, and as it form a slag, it will have problems with continus burning.

 

Make up around 1:1 to 2:1 Nitrate / Copper Oxide.

Did that couple years ago in school a couple years ago. When working on flame colouring. That time we used a mix based on hexamine with around 10-20% Charcoal (of the Hexamin weight). Add a little bit of Copper chloride, to be sure, not to get yellow color.

Probably best to add some Al or Mg to get a high burning temperature

 

@Mumbles if your interested in Flame chemistry, pn me, then i can probably send you a couple quite interesting things about it.

[Jonathan]

CuO and MnO₂ are oxides that give up their oxygen readily to finely divided pure metals. Not to organics.

[Seymour]

Jonothan, they sure do give up the oxygen to finely divided metals, but why do you say 'not to organics' ?

 

Just because you may have mixed CuO and an organic fuel and it did not burn, does not mean that they will not liberate oxygen to organics in any situation. I think your statement is extremely broad, and in many cases incorrect.