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Topic: Methods for Separating Liquid Product from Liquid Reactants In Situ?  (Read 2863 times)

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Offline Arrheinous

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Hi everybody, first time posting to the forums.

I'm working on a solvent-free reaction between a molten reactant (low bp) and a generally insoluble reactant that products a liquid product at around 100C.

The problem I seem to be having is that the reaction goes well at low yields but it seems like there's a rapid polymerization of the product and the insoluble reactant once the population of product gets high enough. The resulting polymer is a huge intumescent grit that fills the container - definitely not ideal. I've gotten 11% yield in 20 minutes but less than two hours later the side reaction occurs.

I'm trying to figure out how to separate the liquid product from the molten reactant. I suppose the easiest method would be to find a low density, high boiling point solvent for the product so it floats on top of the generally insoluble reactants? That's the approach I'm trying now but I'm wondering if there's an apparatus or named method that does what I've described.

EDIT: So it does this side reaction as fast as one hour in... >_>

My idea now is to use some form of Soxhlet extractor - the molten reagent has a high vapor pressure so it can react with the insoluble reagent up in the cup and the product or excess molten reagent drip back down where it can't polymerize itself.
« Last Edit: April 24, 2013, 05:00:59 PM by Arrheinous »

Offline opsomath

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Re: Methods for Separating Liquid Product from Liquid Reactants In Situ?
« Reply #1 on: April 26, 2013, 10:38:04 AM »
It's awfully hard to make reasonable suggestions without knowing more, although it sounds like you may have intellectual property issues with revealing things. At least, what scale is this run on?

Is the side reaction a radical polymerization? You can add something like hydroquinone or BHT to suppress that.

Is the liquid product soluble in the liquid reactant?

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