What happened is the bottom of the beaker start to be burned and the solution is pale yellow color , Is it normal ?
Hello. What is the temperature at which you are heating the solution?
Hello dear, You have to do the following:
1) Weight the amount of PVA and take it to beaker, measure the water amount and start the heating process (90 °C) under stirring until dissolved all PVA.
You also can prepare this solution by employing hot water, but in any case you have to stir the system.
Guido , its from 90-98 not less
Edwin , thanks a lot , i actually heated the water to 90 then i start adding the PVA slowly with continuous stirring but the bottom of the beaker start to be burned and the magnet refuse to stir anymore
This question is a couple of weeks old now, but anyway :)
Just to check: you are dissolving poly(vinyl alcohol) in water? Are you doing this under a condenser? If not, at 90C water will evaporate from this system pretty quickly.
Also, for the avoidance of confusion: are you using partially-hydrolysed PVA, or fully hydrolysed? Partially-hydrolysed PVA is more soluble in water ( because in fully-hydrolysed PVA the inter-chain interaction is greater than the chain-solvent one). Unless your application requires fully-hydrolysed PVA, then you could make your life easier by using a partially-hydrolysed one.
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