Squall181 - 13-6-2011 at 19:31
Does anyone know what the thermal decomposition products of dichloro-s-triazinetrione are.
Reason for my asking is a have some brominating granules that were recently given to me and I would like to know if its worth extracting the sodium
bromide from them. If the products are not extremely toxic maybe this would be a good project to uptake. But the cyanuric acid is kinda putting me off
right now.
woelen - 14-6-2011 at 00:21
First a word of reassurance. Cyanuric acid is non-toxic. It has nothing to do with cyanide and there is no need to fear any cyanide poisoning.
But heating the material to get the bromide is not really interesting. You'll get a horrible charred and very smelly mess and extracting the bromide
from that mess is a real pain in the ass.
You _might_ have some result by adding acid to the solid (finely powdered) product. Bromine may separate, but it depends on the amount of NaBr in the
blend. If there only is a few percents, then the bromine will be further oxidized to BrCl (looks like piss, when in solution) or even to bromate.
Another complication is that cyanuric acid is nearly insoluble in water, so you'll have a white insoluble slurry.
One chemical can be obtained easily from this blend and that is the cyanuric acid. By heating a solution in hydrochloric acid (10%) you boil off
chlorine and bromine chloride and on cooling down, crystals of cyanuric acid will form. These crystals then can be dissolved in a small amount of
boiling water and again allowed to crystallize. Then you'll have nearly 100% pure cyanuric acid.
Getting bromide or bromine from this blend probably is not worth the effort. Pure NaBr or KBr can be purchased easily, it is not a regulated or
otherwise suspect chemical and it is not expensive.
sternman318 - 14-6-2011 at 03:47
If obtaining NaBr is what you are interested in, it is sold in the pool aisle ( I get mine from Walmart , it is a small packet called Brom Start)
Squall181 - 14-6-2011 at 05:04
Thanks for the reassurance woelen and I actually tried to extract the bromide salt from the mix.
What I did is I put 100g of the granules into a SS pot and set it on a hot plate. Turned the hotplate on high and made sure to be as far away as
possible (Outside of course) . What I was left with was a dirty yellow to light brown mass that was very spongy. This I crushed with a glass rod as
much as I could, did not really want to touch it too much or get it in the air. Next I poured about 200 ml of water into a beaker and added the spongy
material. After stirring I filtered off the water and boiled it down until I had crystals forming. Upon cooling more crystals formed and I preformed a
test for the bromide ion using nitric acid and silver nitrate. Test seemed to give positive results.
After drying the product I decided to make some copper bromide on small scale and I seem to have been successful. But you guys are right it is way to
much trouble for a such a small amount of product. And I have seen 99% sodium bromide being sold at pool stores. I just wanted to see if I extract
some. I will try and get some cyanuric acid from it instead. Thanks again for the responses.
Formatik - 14-6-2011 at 08:08
I wouldn't heat any halogenator-containing organic molecules considering compounds like (NCO)2CO, NCl3, or maybe even COCl2 can form.
I'm not sure about dichloroisocyanurate, but Gmelin mentions thermolysis of the related trichloroisocyanuric acid at 240-260 C in an inert gas
atmosphere yields carbonyl diisocyanate (NCO)2CO in 73% yield through chlorine isocyanate (ClNCO) intermediate, and as side-products: NCl3, and small
amounts of Cl2 and CO2.
I don't know exactly how toxic carbonyl diisocyanate is, but the known diisocyanate toluene diisocyanate is extremely poisonous.
Squall181 - 14-6-2011 at 10:28
Well I knew when I was heating the granules that some potentially deadly products could be formed but exaclty what I had no idea.
So I made sure not to stick around for it and I was careful in handling what remained.
Thanks for the info Formatik , I don't intend to repeat this procedure, because I don't exactly like dealing with reactions where I don't know what
all is formed and besides Phosgene doesn't sound like something I want to experiment with.