mewrox99
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Perborate and Pyro
I'm getting some Sodium perborate from HMS-Beagle.
Has anyone done any pyro reactions such as flash powders with this novel oxidizer?
I plan on trying (sub 100mg amounts first) the reaction of Sodium perborate with:
Al 650mesh
Mg 125 mesh
Zn 300Mesh
Sulfur powder
Sugar powder
Anyone had any experiences?
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woelen
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I tried a mix with german dark aluminium powder. This indeed works as flash powder, but it is somewhat hard to ignite. I used easy to ignite BP for
ignition. Another option is using 3% red P in the mix, which also makes ignition much more easy, but its disadvantage is that it makes the flash
somewhat less energetic. But use of red P is not recommended for real pyrotechnics at a larger scale, it is too sensitive and may autoignite on
storage.
I also tried a mix with sulphur, but that sucks. It cannot be ignited at all, it simply smoulders, but nothing more.
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ScienceSquirrel
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Sodium perborate will not be much use as an oxidiser for pyrotechnics.
Compounds like potassium chlorate are extremely oxygen rich. Two moles of potassium chlorate gives two moles of potassium chloride and 3 moles of
oxygen which makes it an effective oxidiser.
Na2H4B2O8 breaks down to give sodium borate and oxygen, the borate will contain quite a lot of the oxygen and sulphur will not be able to reduce
this. However I suspect that aluminium powder might undergo a thermite type reaction which would explain Woelen's results above.
One of the reasons that sodium perborate and percarbonate are so popular in detergent mixtures is because they are strong oxidisers in solution but
only weakly promote combustion.
A piece of paper soaked in strong sodium chlorate solution and dried is very inflammable, a piece of paper soaked in sodium perborate would be only
weakly flammable and the decomposition of the perborate will produce borate which is used to decrease flammability!
[Edited on 9-8-2010 by ScienceSquirrel]
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mewrox99
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I think the 'thermite' like reaction theory is true,
I did a test with Al/(NH4)2S2O8 a while ago. The reaction was like a less hot version of thermite with sulfide left over.
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woelen
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Better results are obtained from K2S2O8. The ammonium ions introduce a lot of gas and decomposition of them also takes quite some energy.
Ammonium-containing compounds sometimes even are used as fire suppressing agents (e.g. ammonium hydrogen phosphate). But what ScienceSquirrel wrote
also applied to peroxodisulfates. These are wonderful oxidizers in aqueous solution, but their oxygen content is too low to be of really good use in
pyrotechnics.
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mewrox99
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I know. K2S2O8 gave ok flash powder with mg (comparable to KNO3) ammonium peroxydisulfate on the other hand did very little with 125mesh Mg
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Mildronate
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I yesterday used 400g K2S2O8 + Al 
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mewrox99
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what sort of reaction did u get,
I never really got Al/K2S2O8 to do anything.
400g of KS2O8/Mg would have been impressive because 400g of really weak flash powder is kwl
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Mildronate
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Do you had real K2S2O8 ? It burn easy.
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mewrox99
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I had K2S2O8 I made from PCB etch (Ammonium persulfate) and KCl
Made quite good flash powder with Mg but not Al (metals are 125 mesh (mg) and 600 mesh dark (Al))
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Mildronate
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I had soviet K2S2O8 and soviet aluminium powder. Mixed together burn easy. I alsotryed with Mg 
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Formatik
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The perborates (also percarbonates and persulfates) also give off ozone chemically when warmed with a few concentrated acids, i.e. heating KBO3.1/2
H2O with conc. H2SO4 forms O3, C.v. Girsewald, A. Wolokitin (Ber. 42 [1909] 865/9). Percarbonates apparently evolve some O3 without heating when conc.
H2SO4 is poured over them. More details on the percarbonate and persulfate methods are also in Gmelin O, 1096.
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Mildronate
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Maybe can make some complex with perborate? Is it posible to make tetramine (II) copper perborate?
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ScienceSquirrel
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It is quite a versatile oxidising agent, particularly in acid solution and it has been used extensively in organic chemistry.
http://www.organic-chemistry.org/chemicals/oxidations/sodium...
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mewrox99
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My perborate has arrived today!
I plan on reacting it with Mg powder and then adding HCl in the hopes of producing pyrophoric borane.
How toxic is it really? If I do it outside how much risk am I in?
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woelen
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Perborate is not the best for making borane. You'd better use plain anhydrous borax. The perborate contains more oxygen (it is an oxidizer) and you
need more magnesium before any borides can be formed.
If you want to make borane, then first heat the perborate for a while. This drives off oxygen and some water of crystallization. The remaining powder
then can be mixed with magnesium powder. Then heat this mix strongly in a test tube. You might want to mix some Mg with perborate and put that on top
of your other powder, in order to make ignition easier.
I'm not really sure whether you can make borane in this way though. Borane is very unstable and IIRC it reacts with water, but let's hope someone else
wiull jump into this thread with more knowledge about boranes.
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mewrox99
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I have borax as well, I'll just heat that to drive off the waters of crystallization
I just want to play with pyrophoricness of borane, I also have some SiO2 so I might make silane sometime
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ScienceSquirrel
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I believe that one of the interesting effects of borane poisoning is auditory hallucinations 
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ScienceSquirrel
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I think you will end up with boron when you react magnesium with sodium borate.
Your best route is the reaction of sodium borohydride with iodine.
http://en.wikipedia.org/wiki/Diborane
Neither chemical is hard to buy where I live but buying them in the States will probably result in an FBI bod stuck up your jacksy
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