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

[Calafalas]

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.

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 ?

 

[chemisttree]

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.

 

[Calafalas]

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 ?

 

[chemisttree]

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.

 

[LudusRex]

Hi there,

It's great to hear that you are working on a polymer reaction and have some questions about the solvent. In order to separate your reaction product from the THF/water mixture, there are a few options you can consider. First, you can try simple filtration as you suggested. Depending on the solubility of your polymer in THF/water, this may be a feasible option. However, if your polymer is insoluble in this mixture, you may need to use a different solvent for extraction. Some solvents that are commonly used for polymer extraction include chloroform, methanol, and hexane. You may need to do some solubility testing to determine which solvent is best for your specific reaction product. Additionally, you may also want to consider using a rotary evaporator to remove the THF and water from your reaction product, followed by purification techniques such as column chromatography or recrystallization. I hope this helps and good luck with your research!