BASF
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PC - an otc source of formic acid ?
Hello all!- It´s been a while since my last post, so i´m glad to contribute again 
The idea is to cook Polycarbonate from compact discs and the like with concetrated NaOH sol. and get valuable formic acid + bisphenol which could be
seperated by extraction or recrystallization.
I am in an early stadium with this idea, so any ideas and suggestions are welcome!
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Nerro
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bisfenol-A is a nerve toxin. I believe it can screw up your reporductive system. Look out.
And you would be left with carbonate and not formate.
#261501 +(11351)- [X]
the \"bishop\" came to our church today
he was a fucken impostor
never once moved diagonally
courtesy of bash
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not_important
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Nerro has it, polycarbonates are called that because they are polymeric esters of "carbonic acid" [-R-O-C(O)-O-R-]n , treatment with NaOH is going to
yield sodium carbonate.
Bisphenol-A is a hormonal mimic, somewhat similar to diethylstilbestrol, it also appears to be able to trigger obesity (some other estrogen-like
compounds act similarly) The only neurotoxicity reports that I know had to do with embryos, appearing to cause early cell death in undifferentiated
nerve cells. I don't know if that's been confirmed, I suppose that if you're an embryo in fairly early stages of development it would be good idea
to avoid exposure to bisphenol-A.
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BASF
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Thanks for the feedback,
i see it now, it should have been obvious 
What about phenoplasts ? they are made of phenol + aldehyde.
A)Phenoplasts should directly break down into the aldehyde and the phenol upon thermal decomposition.
B)At least the phenol should be recovered via NaOH treatment of phenoplast and after acid workup of the phenolate.
A question is still where to get phenoplast-waste these days..
[Edited on 16-7-2007 by BASF]
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not_important
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No go - the basic reactions in the formation of phenol-aldehyde resins are (with Ar being a phenol)
Ar-H + COH2 => ArCH2OH, + Ar-H => Ar-CH2-Ar + H2O
so you've now methylene or other alkane bridges between the phenolic rings. Heating brings about decomposition, but no simple products.
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Nick F
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Here in the UK formic acid is sold OTC as a limescale remover, for kettles, boilers etc. I used it straight out of the bottle with semicarbazide to
make triazolone, for NTO (3-nitro-1,2,4-triazol-5-one, a relatively insensitive high explosive comparable with RDX). I can´t remember the brand name,
but it was sold in little yellow bottles in B&Q, near the "One Shot" drain cleaner that we all know and love. 250 mL bottles, I think. I also
can´t remember the percentage (I did a titration, maybe I wrote the result down somewhere...), but I think, if I remember correctly, that it was
about 60%. There may have been other crap in there, but as far as I could tell it was just a solution of formic acid. There was no soap.
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DeAdFX
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If you don't mind doing a little work I believe formic acid can be made from glycerin and oxalic acid. While not OTC per se it is possible to make it
from fairly common chemicals. I believe organic synthesis(website) should have a procedure for this.
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not_important
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Alternatively make chloroform from ethanol and bleach, evaporate the aqueous part to get sodium format. If you don't want the CHCL3, after the ethanol
has been consumed add excess NaOH and warm the mixture for a long time to convert the chloroform to additional formate.
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Axt
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| Quote: | | Originally posted by DeAdFX... I believe formic acid can be made from glycerin and oxalic acid. While not OTC per se .... I believe organic
synthesis(website) should have a procedure for this. |
Oxalic acid is OTC as a "stain and rust remover" 2kg for cheap, distillation with glycerine gave me at best ~30% formic acid solution (from its
density), never reached the theoretical concentration of ~56%. Though this worked fine for NTO, as brought up by Nick F.
The procedure is in Practical Organic Chemistry by Cohen in SM library.
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Ephoton
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"Alternatively make chloroform from ethanol and bleach, evaporate the aqueous part to get sodium format"
does the haloform reaction work on alcohols I thought it only worked on methyl ketones.
e3500 console login: root
bash-2.05#
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not_important
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Alcohols are oxidised by hypochlorites to the corresponding aldehyde or ketone. Ethanol give acetaldehyde, which undergoes the haloform reaction,
isopropanol gives acetone. Ethanol has the advantage that it directly gives formate and CHCl3, which can be hydrolised primarily to more formate.
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Ephoton
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got you so instead of three moles of hypochlorite per mole of ketone you need four moles per mole
of alcohol.
I have been told that the reaction requires heat then once it starts it is extreamly exothermic. I would guess this means that to create the aldehyde
heat is needed to be put into the system but to do the classic haloform heat is given off.
[Edited on 10-3-2008 by Ephoton]
e3500 console login: root
bash-2.05#
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Aqua_Fortis_100%
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But how to obtain high concentration formic acid from formates?
The only way my little brain can think is, like acetate, reacting the anhydrous formate high % H2SO4 and destill to make it concentrated.. But IIRC,
does not formic react with H2SO4 to give out CO ??? 
"The secret of freedom lies in educating people, whereas the secret of tyranny is in keeping them ignorant."
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Nick F
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Indeed it does. Maybe phosphoric acid could be used? I'm not sure...
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S.C. Wack
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Formic acid is slightly difficult to make from formates and H2SO4 due to decomposition of the acid in the heat of the reaction. In the example given
in GB190920893, 300 parts of around 84% H2SO4 is cooled and 340 parts of dry sodium formate is added with stirring and the temperature maintained at
10-15°. After the addition is complete, the temperature is allowed to rise to 30°, when the temperature suddenly rises, and is kept below 85-90°.
The mixture is stirred for 30 min. at 75°, and is then vacuum distilled, giving 280 parts 81% formic acid in 98% yield. By using 93-96% acid and
keeping the temperature at addition below 10°, and by using serious cooling on the exothermic part of the reaction, they claim 249 parts 90.3% formic
acid, yield 97%.
US1666437 suggests the use of calcium formate, which unlike sodium formate is not hygroscopic, and does not react so quickly with H2SO4 and therefore
does not have such an exotherm to deal with. Even so they use cooling, even though their formate contains almost an equal amount of NaCl due to their
process of making it, and formic acid is added as diluent (60:40:40). The formation of calcium sulfate coating and solids slows down the reaction but
also makes it more difficult for the formate and sulfuric acid to mix. They speak of kneading the mixture!
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Aqua_Fortis_100%
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S.C. Wack , thank you for this info.. I will check out these patents. It seems to be a good way, although I still like the oxalic/glycerin method..
Oxalic acid can be made from sawdust, NaOH, lime and dilute H2SO4 (according with very great papers you and not_important attached in another thread),
and with this you can recover the NaOH (using lime) and use that several more times what make it still more OTC. Also, a small amount of formate is
produced in this process along with oxalate, but I dont know how to better stract it, since is usually a small amount. I have tried it.. The procedure
is somewhat tiresome and messy, but is also easy and finding the reactants are even more.
I just dont remember so well, but in megalomania page he recommend to use anhydrous precursors to get better concentrations of formic..I'm just
wondering how strong the destilate can be, since a small amount of water is either produced or present with reactants even in an "anhydrous" state
(just guessing  )..
little off-topic:
Nick F , how much % is your limescale remover and how much TO you produced using this product (yield)? Do you make your own SCA*HCl or just buy it?
Also, what was your yield of NTO?
Long time ago I have heard (microtek, IIRC) that using lower conc. formic to make TO will give poorer results in overal yield... Did you find this
true with your experiment?
Thanks
[Edited on 20-5-2008 by Aqua_Fortis_100%]
"The secret of freedom lies in educating people, whereas the secret of tyranny is in keeping them ignorant."
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Picric-A
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one could use sodium hydrogen (bi)sulphate to distill of formic acid from formate salts.
One problem of making formate slats via the bleach/ethanol haloform route is there will be a significant quantity of NaCl impurity in it form the
hypochlorite so as well as distilling of formic acid you will be distilling of HCl
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