How do I synthesize pentaerythritol?

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Offline R RAJESH

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How do I synthesize pentaerythritol?
« on: 23/05/2016 20:25:03 »
hi friends
   how to control the formation of tripentaerythritol in reaction itself.i am doing a research on production of pentaerythritol . but am facing a problem with more tripentaerythritol formation.

Please phrase all topics as a question - moderator
« Last Edit: 23/05/2016 22:18:38 by evan_au »

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Offline chiralSPO

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Re: How do I synthesize pentaerythritol?
« Reply #1 on: 23/05/2016 23:59:13 »
ummm...

well, how are you trying to do it, and how is it going wrong?

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Offline R RAJESH

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Re: How do I synthesize pentaerythritol?
« Reply #2 on: 24/05/2016 20:22:44 »
well . . .the reaction was carried out under base condition
*acetaldehyde react with farmaldehyde in presence of caustic
*molar ratio of Fa/Aa -5.1
*Aa was added in a control rate
*reaction end temp was around 45-47 deg

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Offline chiralSPO

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Re: How do I synthesize pentaerythritol?
« Reply #3 on: 24/05/2016 23:04:03 »
Well, to avoid formation of oligomers of pentaerythritol, you might want to decrease the concentration of the reactants. You also did not specify which base or how much of it was being used. It is possible that the conditions are too alkaline (or not enough!).

I believe that either calcium hydroxide or potassium hydroxide are the favorite bases for this reaction.

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Offline R RAJESH

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Re: How do I synthesize pentaerythritol?
« Reply #4 on: 25/05/2016 11:21:25 »
Sodium hydroxide is used . . and after reaction-  PH 10 to 11
Fa/As molar ratio will make any difference in reaction . .
Decrease the concentration of reactant ?? Need more information

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Offline chiralSPO

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Re: How do I synthesize pentaerythritol?
« Reply #5 on: 25/05/2016 13:43:53 »
Try doubling the volume of water used for the same amounts of FA, AA and NaOH. The reaction may take longer, but there should be significantly less trimer.