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Author: Subject: Alcohol borates synthesis
DalisAndy
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[*] posted on 21-10-2015 at 16:29
Alcohol borates synthesis


For making triethyl and triisopropyl borate, I have found a cheap $5 USD, source of both boric acid and a sulfuric acid source. Pic Orthoboric acid roach and ant killer contains the polyboate Na2SO4•H3BO3. That should allow you to synthesize triethyl and triisopropyl borate without having to buy sulfuric acid



Elements Collected: 19/81 (Excluding all radioactive, using placecard for those)

Any tips or good sources are welcome.
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gdflp
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[*] posted on 21-10-2015 at 18:11


That won't work. Esterifications require a strong acid, and that is not a strong acid. You either need sulfuric acid or perchloric acid, or you can directly bubble hydrogen chloride into the reaction mixture.



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DalisAndy
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[*] posted on 21-10-2015 at 18:53


The Na2SO4 will recombine with the H3BO3 to form Borax and sulfuric acid in solution



Elements Collected: 19/81 (Excluding all radioactive, using placecard for those)

Any tips or good sources are welcome.
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Detonationology
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[*] posted on 21-10-2015 at 19:36


Quote: Originally posted by DalisAndy  
Pic Orthoboric acid roach and ant killer contains the polyboate Na2SO4•H3BO3.

I have this brand boric acid and it works well for trimethyl borate. Na2SO4 will not make H2SO4 in solution. You will need sodium BIsulfate (NaHSO4). The first protonation in water yields Na+ and HSO4- ions, then the second yields H+ and SO4-2. The H+ is what is necessary to catalyze the reaction, that's why a strong acid like H2SO4 is used. The 3 hydrogens in H3BO3 react with 3 OH groups belong to the alcohol to yield 3 atoms of H2O.

[Edited on 10-22-2015 by Detonationology]




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Amos
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[*] posted on 22-10-2015 at 05:20


Quote: Originally posted by DalisAndy  
The Na2SO4 will recombine with the H3BO3 to form Borax and sulfuric acid in solution


Nope. Firstly, sodium sulfate isn't even soluble in alcohol, and any water present will only serve to impede the reaction. Secondly, sulfuric acid is a stronger acid than boric acid by many orders of magnitude, and the amount of boric acid produced by the equilibrium is negligible if any at all.




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gdflp
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[*] posted on 22-10-2015 at 06:44


Quote: Originally posted by DalisAndy  
The Na2SO4 will recombine with the H3BO3 to form Borax and sulfuric acid in solution
It will not due to equilibriums. Sulfuric acid is a strong acid, while boric acid is a rather weak acid. Thus, if you mixed a solution of sodium borate and sulfuric acid, it would form sodium sulfate and boric acid. However, the reverse will not happen due the low pKa of both sulfuric acid and bisulfate ions. Esterifications require a strong acid to accomplish certain protonations, and boric acid is incapable of doing so.



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vaiby23
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[*] posted on 27-10-2015 at 23:32


hello friends i wanna make 2kg batch of trimethyl borate in lab please help.:o
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Hawkguy
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[*] posted on 28-10-2015 at 12:39


Why do you need 2kg of Trimethyl Borate?
EDIT
I think I know.. Green fire n stuff. Imma try mixing it with instant snow soon ;)

[Edited on 28-10-2015 by Hawkguy]
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