INDUSTRIAL AND ENGINEERING CHEMISTRY
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portions, and the percentage composition on a dry basis was calculated for each mixture. From each mixture, two films (0,002inch dry thickness) were cast. One film was allowed t o dry for 16 hours under room conditions. and the other was dried for 16 hours in an oven a t 105" C. Eahh film was cut into small pieces, which were immersed in aaueous buffer solutions of varying DH. After standing 1 hour a t rdom temperature the solubiliig Gf -the films a t various pH values was rated visually.
Vol. 45, No. 10
LITERATURE CITED
(1) Dyer, E., and .
