When I precipitate a polymer, it forms a liquid precipitate. I want to obtain a solid form. I usually use methanol as the antisolvent. Can someone provide information about this situation...?
Dear Bae Inhui, I have already answered this question! But it seems that my answer is not taken by the system! I said may be the molecular weight is too low, i. e , of the order of an oligomer. Check the MW to confirm or deny this assumption. What is the solvent? May be methanol is not the best anti solvent. My Regards
Abdelkader BOUAZIZ First, I want to thank you for answering my question. I use DMF as a solvent, and I also use DMAc. This experiment involves the substitution of polymer. If the molecular weight is too low, does it mean the polymer molecular weight is low or the copolymer molecular weight is low?
No thanks, you may suspect many possible reasons. Check the stability of the unmodified polymer under the modification conditions, mainly thermal and shear. Degradation during modification may reduce MW. If this is not the case, may be the modification render the virgin polymer more or less soluble in both DMF and methanol. Another possible reasons is that the modification provoke spacing chains, reducing thus the intermolecular cohesion, and increasing the free volume which will be occupied the binary solvents mixture. Hope these help and guide you to settle the problem.
- Badges
- Science method
- Similar topics
- Methodology
- Crystallography
- X-ray Diffraction