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Levi
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| Quote: | Originally posted by __________
How much sodium percarbonate does oxyclean contain and how can you isolate it? |
The back of the container says "contains sodium percarbonate and sodium carbonate" but it doesn't list how much of each. I interpret this as "at
least 50%," since it's listed first. I have no clue how one might isolate it. Aqueous extraction is out of the question since percarbonate
decomposes on solvation. I expect they have similar solubilities in other media but I'm not sure. Centrifuge? 
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Aqua_Fortis_100%
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| Quote: | originally posted by nitro-genes:
I've tried the synthesis of TCAP and HMTD with neutralized percarbonate solutions a long time ago already. It really becomes a mess though. I used 10%
hydrochloric acid to neutralize, but a small spoonfull of this percarbonate goes a long way!
I got something like halve a gram of TCAP after 3 days of reaction, and from almost 50 grams of percarbonate in 300 ml HCL IIRC. Vast quantaties of
NaCl precipitated from the cold during these 3 days and the resulting TCAP was heavily contaminated as was evident from the bright yellow light the
TCAP emitted upon ignition...
I had no luck using nitric acid to neutralize the carbonate for the formation of any HMTD.
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1/2 gram of TCAP from 50g percarbonate?! Pretty,pretty poor yield!!
You destroied my hope of one day try this!
for the HMTD: Tried you get in different temperatures and others conditions or you used only < 10°C, slightly acids, etc ????
i thinking around perborates, but this is much more hard to find than percarbonate (at least here)...
what you think about?
edit: luckily i can buy 50% H2O2 for something as US$ 2.50 (converting) a liter.. at the moment i have 10 liters ..
[Editado em 22-3-2007 por Aqua_Fortis_100%]
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nitro-genes
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For the synthesis of 3-nitro-4 acetaminophenol, I've found a way to produce fairly concentrated h2o2 solutions from percarbonate (15%), reasonably
free of salts using no disitillation. Not sure if I should post this though...
[Edited on 7-6-2015 by nitro-genes]
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AJKOER
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Having researched and worked with these over the counter percarbonate products, some suggestions.
1. OxiClean, per labeling laws when percarbonate is listed as the 1st ingredients, has in the majority by weight, Na2CO3.(3/2)H2O2, but a significant
amount of Na2CO3 also, which is listed as the second ingredient, and still worst perfumes and other organics. I recall an online article discussing
the actual amount of H2O2 in OxiClean and a relative comparison to other percarbonate products. Best advice, buy a generic substitute (usually bearing
the store's name) which, in my experience, is least absent the perfumes.
2. Research this forum on the preparation of peroxides, like CaO2, for example, which I have prepared (link: http://www.sciencemadness.org/talk/viewthread.php?tid=17052&... ) which can start with just dilute 3% H2O2. I suspect treating the freshly
prepared moist CaO2 with CO2 should liberate a strong, but unstable, H2O2 via:
CaO2 + H2O + CO2 --) CaCO3 (s) + H2O2
Working with Barium salts I personally find unappealing (toxicity perceptions).
Bottom line, forget the percarbonates unless you are doing your laundry. OxiClean and other like percarbonates are great at what they were designed to
do, rapidly dissolve and liberate oxygen.
[Edited on 7-6-2015 by AJKOER]
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nitro-genes
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Generally I agree, yield of hydrogen peroxide on basis of percarbonate is not that high, but the precess works, even with 30% percarbonate laundry
cleaner. Basically, you neutralize the percarbonate with 37% sulfuric acid at room temperature in a large container while stirring, until most of the
percarbonate has dissolved, liberating the hydrogen peroxde. Then you filter out the undissolved carbonate/percarbonate and add an equal volume of
ethanol or methylated spirits and put it overnight in the freezer, this will precipitate almost all of the sodium sulfate as a hydrate (the loss of
hydrogen perxoide due to forming an adduct with the sodium sulfate is unknown, but probably existent). It is important that the solution is near
neutral (or better, slightly acidic to stabilize the H2O2), since sodium hydrogen sulfate will refuse to precipitate and the ethanol will just form an
unmixed layer on top of the HSO4 solution. After some mixing and overnight cooling, the massive amount of sodium sulfate hydrate formed is filtered
out and the solution boiled to drive off most of the ethanol. The hydrogen peroxide solution formed can probably be used for most reactions, long term
stability unknown.
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diggafromdover
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Actually, you can buy straight sodium percarbonate on EBay. I use it instead of Oxi-Clean.
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nitro-genes
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Yes, I would advice extreme caution though when using 100% percarbonate/ Precipitation of the sodium sulfate as the hydrate probably increases the
concentration of the hydrogen peroxide considerably. You don't want to boil down 50% hydrogen peroxide + ethanol! Probably better to just let the
ethanol slowly evaporate.
TAKE EXTREME PRECAUTIONS WHEN USING 100% percarbonate, REALLY
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