Hello,
I'm working on PEG-PLA (5000:15000 Da) and I try to purify it after ROP polymerization. In different papers, they use purification by precipitation (usually with MeOH or diethyl ether) but I'm working with small amount and I don't succed to purify (500-700 mg). After adding the co-solvent i see the solution turn white but it's to small to filter (i may plug...). Do you have solution for me ? Thanks :)
DearLouise Van Gheluwe, membrane dialysis followed by freeze-drying. My Regards
You can also try centrifuging to drive ppt to bottom of centrifuge tube - easy to remove supernatant above “pellet” of product.
Dear, I purify my PEG-PLA (little amount) in cold pentane: let stir your copolymer in cold pentane overnight, after you can place the vial in a fridge, and after precipitation of the polymer, remove the supernatant and dry the polymer under vacuum .
Abdelkader BOUAZIZ Is it possible? I have lactide (monomer) in large quantities that I must get rid of (and SnOct2) and it will not be soluble in water?
I am not familiar with dialysis ... Do you have more advice about this technique ?
James E Hanson I have already try to centrifuge but i don't have pellet (just 5 mn at 100 RCF). I don't know how much RCF I can use with an organic solvent. I only test 5 min at 100 RCF.
Bolley Anaëlle We do not have pentane in the laboratory because considered too harmful. Hexane maybe ?
Thanks all :)
Dear all, these are additional information. Hydrolysis leads to the acid form which is water soluble. For the other component I think short column chromatography will eliminate it. Other thing is that PEG-PLA is a conventional diblock copolymer, be sure there is (are) optimized purification procedure. I have many papers on PEG copolymers but no time to find those concerned by the question. My Regards
I checked the solubility of stanous octoate. Solubility in water: (4.585 mg/l @ 20 °C). I think the concentration you used is below, if not just do dilution before membrane dialysis. My Regards
Hi;
You can use the centrifugation technique. Please see the reference below:
http://www.scirp.org/journal/ajac http://dx.doi.org/10.4236/ajac.2016.73028.
Best regards
Dear Louise Van Gheluwe, recently for PLA (PLGA) purification we also used reprecipitation method, but slightly modified it: polymer solution in chloroform added to ethyl alcohol by drop-wise under vigorous stirring (on magnetic stirrer). It allowed us to obtain thin filament-like particle, which filtered significantly better.
You can try with heated toluene (40°C), then by cooling the solution you can obtain the solid polymer for filtering under vacuum
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