Hi - I am trying to make a 5wt% PVA (MW=130000) in water solution. I heated it for several hours at 90 degC while stirring, and left the solution to continue to stir overnight. I was able to watch the dissolution process as the PVA became more swollen and fully dissolved. However, the solution still has a lot of cloudiness and particulates throughout. I was unable to filter out (0.45um syringe filter) the particulates because of the viscosity of the PVA solution ... has anyone else had issues with these particulates and know how to either remove them or fully dissolve them into the solution?
As you know, poly(vinyl alcohol) - PVA- is NOT made by the polymerization of its monomer since vinyl alcohol "an unstable enol system" simply does NOT exist. Instead, PVA is made by the hydrolysis of poly(vinyl acetate) & in many instances, the hydrolysis is incomplete.
Therefore, the cloudiness you observed in the solution is normal & is indicative of the presence of some unhydrolyzed vinyl acetate units.
The link, below, claims that it has a method for complete dissolution of PVA so it is worth trying with some modification.
https://support.ultimaker.com/hc/en-us/articles/360011959100-How-to-dissolve-Ultimaker-PVA
Dear Emily Schafer,
I suggest you to verify the following links. I hope it would be useful.
https://www.silverson.com/us/resource-library/application-reports/preparation-of-polyvinyl-alcohol-pva-solutions
https://www.sciencedirect.com/topics/medicine-and-dentistry/polyvinyl-alcohol#:~:text=PVA%20was%20used%20as%20a,was%20dissolved%20in%20the%20water.
- Badges
- Science topic
- Similar topics
- Physical Sciences
- Materials Science