Due to the high b.p of DMSO and DMF (189 and 153 degree Celsius), it is difficult to recover my polymer from the solution. I believe extraction in a triple system (such as DCM, DMSO and water) would serve as an alternative. Can anyone tell me if this technique would work? if not, please suggest another method.
(due to excess solvent, I cannot do precipitation directly)
Thank you
Dear Anjali Preman, it seems difficult to give a hint without knowing the nature of the polymer. These links may bring some help. My Regards
https://doi.org/10.1002/pi.4980200403
https://www.researchgate.net/post/How_to_dry_polymer_from_DMSO_solution
Thank you Abdelkader BOUAZIZ
The polymer is Upy-acrylate-co-t-butyl acrylate in DMSO
Upy = 2-ureido-4-pyrimidone
I used to regularly run reactions in DMSO. My standard extraction was with brine (salt water), NaHCO3, and hexane. In this case, the organic product goes into the top (hexane) phase. Depending on your product, you may have more success with DCM. Although here, you will be interested in the bottom (DCM) phase. I personally prefer CHCl3 to DCM, since it is denser and thus partitions from H2O/DMSO better. Also, the very low bp makes it come off too fast on the rotovap. Another note, you will need to use much more water than DMSO to get a proper partition. Thus, you may need a very large separatory funnel.
Dear Anjali, when you do polymerisation in DMSO or DMF, after 24-48 hr just check whether it can be precipitated in cold diethyl ether or cold methanol( depending upon the nature of your compound). If it gets precipitated in any of the solvents, then do the reprecipitation in cold solvents several times and then keep the polymer in Vaccum oven. I hope this will help.
My regards.
Hi;
To remove DMSO, a common method is to wash with water and extract with a lower boiling point organic solvent like DCM. You can also remove the DMSO by lyophilization (freeze drying) after water dilution.
With my best regards
Thank you Samuel Clark Ligon , I was also thinking on this triple extraction, but since CHCl3 and DCM are miscible with DMSO , I am not sure how does it work, Can you please make it clear?
Thank you Shivani Goyal , Precipitation seems an easy method, but would it be possible to precipitate the product from a very large amount of solvent? (say 20-30 ml)
Dear Anjali Preman, don't dilute the solvent used for the polymerisation reaction, just precipitated the reaction mixture directly. Say for 100mg, rection mixture solvent is 1ml, then use around 50-60 ml of cold solvent to precipitate. Reaction solvent should be minimum in amount during precipitation. So either concentrate the solvent before precipitation or take less amount of solvent in starting itself or take the cold solvent for precipitation in the large amount.
My Regards.
Dear Anjali
You do better use cold water as a non solvent if your polymer can be precipitated in water. DMSO and water are miscible so you can separate your polymer by simple filtration. For example for 10 ml of your solution of DMSO you have to use at least 70 ml of cold water
Dear Anjali, Reprecipitation method using excess amount(thrice of the polymer solution) of water(most preferred) or methanol would be the best method if I'm not wrong.. You can get back your polymer..
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