How Can I Separate My Polymer Reaction Product from the THF/Water Mixture?

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Discussion Overview

The discussion revolves around the separation of a polymer reaction product, specifically Cyclopentadiene functionalized polyketone, from a THF/water mixture. Participants explore various methods for isolating the polymer from the solvent and any accompanying salts, focusing on practical techniques and challenges encountered during the process.

Discussion Character

  • Experimental/applied
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant suggests that the polymer will be less soluble in THF/water, particularly with increased water content, and proposes using cold water to isolate a crude solid after the reaction.
  • Another participant notes that filtration may not be effective due to the stickiness of the product, recommending centrifugation or using a rotavapor to remove THF and facilitate the isolation process.
  • A participant shares their experience of unsuccessful filtration after attempting to reprecipitate the reaction mixture in water, indicating that only a small volume could be filtered before clogging occurred.
  • Suggestions include decanting the mixture, adding THF, and reprecipitating into cold water, as well as drying the product under high vacuum to achieve a friable solid.

Areas of Agreement / Disagreement

Participants express differing views on the effectiveness of filtration and the best methods for isolating the polymer, indicating that multiple competing approaches are being discussed without a clear consensus on the optimal solution.

Contextual Notes

Challenges mentioned include the stickiness of the polymer affecting filtration, the need for specific solvent ratios, and the potential for clogging during the filtration process. There are also unresolved steps regarding the purification and drying of the final product.

Calafalas
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Hi chemistry friends,

I'm currently working on a reaction to produce the following polymer: Cyclopentadiene functionalized polyketone.

I start with polyketone as a reagent and I should end up with the reaction product together with the solvent (THF) and water with NaOH.

4863134612_9b21a61ab3_z.jpg


My question is as following: How can I separate my reaction product from the THF/water ?
Do you think that is will be insoluble in THF/water, so I can use simple filtration? Or should I use a different solvent to extract the polymer ?
 
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It should be much less soluble in THF/water. The more water the less soluble. You might need to add more THF or dioxane to keep it in solution long enough to complete the grafting. After that, pour the stuff into a large volume of cold water and isolate a crude solid. Dissolve in a minimum of dioxane and repeat to further purify and reduce the amount of salts in the product.
 
Tried to repricipitate the reaction mixture in water. Filtration doesn't seem to work however.. only for about 5 ml. Then it stops.
Any tips for this ?
 
The stuff is sticky and clogs your filter's pores. Try centrifuging. Or you could put the whole thing on the rotavap and remove the THF solvent. It should goo out on the glass surface eventually. Decant, add some THF and reprecip into cold water. If you still have troubles with the precipitation/filtration or centrifuging, put it back on the rotavap and remove the THF again. Dry the goo under high vacuum and hope that when the last traces of solvent and water are removed you get a friable solid so you can scrape it out, grind it and properly dry it.
 

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