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Dehydration studies of PVOH and Measuring Intrinsic Viscosity
Addition of Acid to thin films of PVOH was done in a following way.
In 1.0 g 100,000 MW PVOH solution, 2 drops of hydrochloric acid was added. In 1 g 22,000 MW PVOH solution, 1 drop of phosphoric acid solution was added. In 0.5 g of 100,000 MW solution of PVOH, 2 drops of hydrochloric acid was added. In 0.5 g of 22,000 MW solution of PVOH, 1 drop of phosphoric acid was added.
22,000 MW and 100,000 MW PVOH was selected to do the intrinsic viscosity determination. The stock solution of 22,000 MW PVOH solution with a concentration of 1.0g/100 ml was prepared. Also, 100,000 MW PVOH was used to make a stock solution of 1.0g/100 ml.
The solution of 22,000 MW of PVOH was heated with slow stirring to 90 degree Celsius.
5 g of PVOH was added over about 30 mins with sporadic heating.
The resulting solution was allowed to cool at room temperature.
After cooling, the solutions were transferred into 20 ml Erlenmeyer flask
Several dilutions of the original polymer, 22,000 MW were made in the following dilution scheme to create calibration curve: Original 22,000 MW PVOH: stock, 3/4, 1/2, 1/4, an 1/8
The same procedure was repeated with 100,000 MW PVOH.
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