Partially neutralized AA was used as monomer and polymerization carried out in aqueous medium.
You can use the suspension polymerization process. You will get beads that you can usually dry to obtain a powder.
Dear all,
this means that the gel is highly hydrated, since polyacrylic acid is highly hygroscopic. Freeze drying, soxhlet drying or azeotropic distillation may be helpful to get the powder form of the gel. Regards
you can dry them fully ,then freeze them .Afterwards They can be crushed to powder by wrapping in a clean thick sheet .
Dear Ahasanur,
Depending on the extent of crossslinking in your PAA hydrogels it may be very difficult to completely dry your hydrogels. In any case you should shred your hydrogels into as smal particles as possible and then vacuum dry. Even in the dried form they may still contain some so-called bound water which is difficult to dry completely.
Dear all,
if the problem water content is still persistent; I think the best way is to perform the polymerization in an organic water free solvent. This will alow to avoid additional workup task after the polymerization. Regards
An alternative way is swelling the hydrogel in distilled water up to its equilibrium. Then, you can break the swollen hydrogel using a spoon. The broken hydrogel should be dried in an oven at 30°C for 48h. After that, you can pulverize it using a mortar.
Please see this reference
http://link.springer.com/article/10.1007%2Fs00396-015-3744-z
Have you tried to wash your rubbery hydrogel with methanol before drying it several hours at 60oC ?
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