[infectus]

Hi,

I'm a french trainee who work for a PVC industry.
I work on the validation techniques for the good dissolution of polyvinyl alcohol.
Anyone know a technique for showing that polyvinyl alcohol are well dissolved in water.

Sorry for my english and thanks if you can help me 

[wildfyr]

Mix a given amount of it in 90C water, then let it cool and filter. Remove whatever gets caught in filter and dry it. This will give a measurement of solubility of a given PVA in water.

[hollytara]

PVA is usually pretty soluble - but it does depend on MW and the percent of hydrolysis from polyvinyl acetate.  It can be a little odd also - sometimes it is more soluble in cold water.  But using a standard quantity and a standard volume of water at a standard temperature allows you to compare.  After filtering, I always prefer to measure what IS in the water - take a standard volume (100-1000 microliters) and put it in a small tared beaker, then evaporate to dryness, then weigh to see how much PVA is in the solution. 

[infectus]

thanks for your reply .
I have try to dissolve the PVA at 90°C during 30min but it did not work . I have let the agitation during the night and its dissolve.

For know if all is well disolved i have pass the sample on the dessiccator but i thinks it's not the good maner.
I heard about a method with iodine. Have you heard of it before?