Everything about Cyanuric Acid totally explained
|Section2=
|Section3=
}}
Cyanuric acid or 1,3,5-triazine-2,4,6-triol is an
chemical compound with the
formula (CNOH)
3. Like many industrially useful chemicals, this
triazine has many synonyms. This white solid is the cyclic
trimer of
cyanic acid, HOCN. It finds use as a precursor or a component of
bleach, disinfectants, and herbicides.
Chemical and properties
Cyanuric acid is odorless,
hygroscopic, and commonly used as a crystalline powder. On heating above 320 °C, the solid decomposes to
toxic nitrogen oxides and
cyanic acid.
The two
chemical structures shown in the infobox readily interconvert: they're
tautomers. The triol tautomer has
aromatic character. Consequently, the
hydroxyl (-OH) groups assume
phenolic character, becoming more
acidic than hydroxyl groups in typical
alcohols. Deprotonation with base affords a cyanurate
salt.
Synthesis
Cyanuric acid (CYA) was first synthesized by
Wöhler in
1829 by the thermal decomposition of
urea and
uric acid. The current industrial route to CYA entails the
thermal decomposition of urea (thermal decomposition). The production of CYA and
ammelide commence simultaneously at approximately 175 °C, in the following two reactions involving both
biuret and
isocyanic acid as intermediates:
» H
2N-CO-NH-CO-NH
2(m) + HNCO(g) → CYA(s) + NH
3(g)
H
2N-CO-NH-CO-NH
2(m) + HNCO(g) → ammelide(s) + H
2O(g)
As temperature exceeds 190 °C, other reactions begin to dominate the process.
The first appearance of
ammeline occurs prior to 225 °C and is suspected also to occur from decomposition of biuret but is produced at a slower rate than that of CYA or ammelide, by the following reaction:
» H
2N-CO-NH-CO-NH
2(m) + HNCO(g) → ammeline + 2 H
2O
The first appearance of
melamine occurs between 325 and 350 °C and only in very small quantities.
Cyanuric acid can be produced by hydrolysis of crude or waste
melamine and isolating the pure cyanuric acid product by crystallizing out and filtering off the cyanuric acid. Acid waste streams from plants producing these materials contain cyanuric acid and on occasion, dissolved amino-substituted triazines, namely,
ammeline, ammelide and melamine. In one method, an ammonium sulfate solution is heated to the boil and treated with a stoichiometric amount of melamine, by which means the cyanuric acid present precipitates as
melamine cyanurate. The various waste streams containing cyanuric acid and amino-substituted triazines may be combined for disposal and during upset conditions, undissolved cyanuric acid may be present in the waste streams.
Applications
Cyanuric acid is used as a
stabilizer in recreational
water treatment to minimize the decomposition of
hypochlorous acid by sunlight in outdoor
swimming pools and
hot tubs. It achieves this by absorbing UV radiation.
Chlorinated derivatives of cyanuric acid, such as
trichloro-s-triazinetrione and
sodium dichloro-s-triazinetrione, are used as algacides or microbiocides in swimming pool water and large scale water systems in industry.
Testing for cyanuric acid concentration is commonly done with a turbidometric test, which uses a reagent, melamine, to precipitate the cyanuric acid. The relative turbidity of the reacted sample quantifies the CYA concentration. Referenced in 1957.
This test works because melamine combines with the cyanuric acid in the water to form a fine, insoluble, white precipitate that causes the water to cloud in proportion to the amount of cyanuric acid in it.
FDA permits a certain amount of cyanuric acid to be present in some
non-protein nitrogen (NPN) additives used in animal feed and drinking water. Cyanuric acid has been used as NPN. For example,
Archer Daniels Midland manufactures an NPN supplement for cattle, which contains
biuret,
triuret, cyanuric acid and
urea.
2007 pet food recalls
Cyanuric acid is implied in connection to the
2007 pet food recalls, the contamination and wide recall of many brands of cat and dog foods beginning in March 2007. Research has found evidence that cyanuric acid together with
melamine forms poorly soluble crystals which can cause renal failure. The evidence is as yet inconclusive.
Further Information
Get more info on 'Cyanuric Acid'.
|
External Link Exchanges
Do you know how hard it is to get a link from a large encyclopaedia? Well we're different and will prove it. To get a link from us just add the following HTML to your site on a relevant page:
<a href="http://cyanuric_acid.totallyexplained.com">Cyanuric acid Totally Explained</a>
Then simply click through this link from your web page. Our crawlers will verify your link, extract the title of your web page and instantly add a link back to it. If you like you can remove the words Totally Explained and embed the link in article text.
As long as your link remains in place, we'll keep our link to you right here. Please play fair - our crawlers are watching. Your site must be closely related to this one's topic. Any kind of spamming, dubious practises or removing the link will result in your link from us being dropped and, potentially, your whole site being banned. |
