[koral]

Hi All,
I have monomer Methly-Acrylate coming with an MeHQ inhibitor inside.
I would like the polymerise the monomer with a comonomer, so i have to remove inhibitor prior polymerisation.

One method (I read from an article) is to wash monomer with aqueous NaOH caustic solution. So, the MeHQ reacts with NaOH, turns into salt.
Then, we will have a mix of two liquids, Methyl-acrylate monomer and water (containing NaOH and salt of NaOH/MeHQ).
After, these two liquids can be separated by using funnel.

But, i read that there will be small amount of water dissolved in Methyl-Acrylate phase.
So that means, after i collect Methly-acrylate at bottom of the funnel, there will be small amount of water and dissolved NaOH in monomer.
And, i do not want this residual NaOH because it can affect the quality of polymerisation process.
- How can i minimise the residual Water/NaOH solution in Methyl-Acrylate ?
- If i do : Let's say first i wash Methyl-acrylate with 0.1N aqueous NaOH , and second wash with 0.05N , and third wash with 0.01 N. That would be a good solution to remove all MeHQ and minimise the NaOH in Methyl-Acrylate ?

Please, let me know if there are any other precise way to do this.

Regards.

[TheUnassuming]

Any time you do an aqueous/organic extraction, the separation between the phases is never 100%.  There will always be some water in the organic layer and organic solvent in the water layer.  How much will depend on which organic solvent you are using and salt concentration/type in your aqueous layer.   Before I make assumptions, have you done liquid extractions before in lab?

[koral]

No, this is the first time i will do this process.

[TheUnassuming]

Ah, well welcome to the wonderful world of working in a wet lab! 

Ok, when you do a liquid/liquid extraction, you always want to dry the organic layer before concentrating.  In practical terms, that means you slowly add in sodium sulfate or magnesium sulfate while swirling your organic layer until it no longer clumps up, then filter the solids off to get your "dry" organic layer.  If you have impurities that are also coming along for the ride with water (organic salts usually), they should also crash out/adhere to the solids as well.  In your case, you are working neat, so you should be able to just add the drying agent directly to the methyl acrylate before filtering off.   

[koral]

Thank you TheUnassuming, that was very helpful.

[DrCMS]

I have monomer Methly-Acrylate coming with an MeHQ inhibitor inside.

Yes that is normal.

I would like the polymerise the monomer with a comonomer,

Yes a normal thing to do with a monomer

so i have to remove inhibitor prior polymerisation.

WHY?  Just us a little bit more initiator.

[wildfyr]

WHY?  Just use a little bit more initiator.

Virtually always the easier answer.