The mixtures were stirred to obtain a good blend, and the films made by casting 40 mL on 144 cm2- square plates, drying afterwards at 40 C in a forced-air oven for 16e18 h to yield a uniform thickness in all cases (200 mm).
The mixtures were stirred to obtain agood blend, and the films made by casting 40 mL on 144 cm2- square plates, drying afterwards at 40 C in a forced-air oven for16e18 h to yield a uniform thickness in all cases (200 mm).