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Author: Subject: Nitrocellulose not precipitating.
idrbur
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[*] posted on 8-7-2020 at 20:24
Nitrocellulose not precipitating.


So, i was trying to make some nitrocellulose. Usually i make it by placing some cotton into 1:3 HNO3 and H2SO4 for 3 hours which results in alot of wastage of acid. So thus time i tried dissolving cotton into 5 part H2SO4 at 0 degree celcius and then slowly added 2 part HNO3 maintaining 0 degree C. Then stirred it for 3 hours. To seprate it i added lot of cold water to it but there was no precipitate at all the solution just turned a yellowish. Can someone please tell what i did wrong.
Thanks in advance
(I found this procedure in a manual i found online)
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Syn the Sizer
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[*] posted on 8-7-2020 at 20:43


I have never had my cotton dissolve nor have I ever had precipitate, I believe your cotton is now gone. I have always gone the NaNO3 and H2SO4 route, well my first time was Ca(NO3)2 and H2SO4 but it left lots of soot.

According to this Science Madness Wiki stub you want equal parts HNO3 and H2SO4. You will also want to chill it before you add the cotton.
http://www.sciencemadness.org/smwiki/index.php/Nitrating_mix...

Adding the cotton directly to the pure H2SO4 destroys it, just like it when you pour it on paper towel.

[Edited on 9-7-2020 by Syn the Sizer]
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B(a)P
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[*] posted on 8-7-2020 at 21:10


Your cotton did not dissolve it was destroyed.
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idrbur
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[*] posted on 8-7-2020 at 23:29


Well that's a little disappointing to know.
Anyway, thanks for your reply.

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Herr Haber
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[*] posted on 10-7-2020 at 01:46


3 hours nitration is inviting for trouble anyway
If your cotton is clean enough it can be done in less than 30mn around 20 degrees.
If it isnt clean you'll get a runaway and that yellowish soup you got.




The spirit of adventure was upon me. Having nitric acid and copper, I had only to learn what the words 'act upon' meant. - Ira Remsen
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idrbur
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[*] posted on 10-7-2020 at 16:46


Isn't 20 degree celsius a little high for nitration?
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B(a)P
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[*] posted on 10-7-2020 at 17:05


Quote: Originally posted by idrbur  
Isn't 20 degree celsius a little high for nitration?


It depends what you are nitrating. I do my NC at room temperature. The nitration of phenol happens at a much higher temperature. If you are nitrating etythritol that needs to be near 0, at least at the start.
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