A film sample (0.2 g) was weighed into aluminum crucibles
and dried at 105 C in an oven with forced air circulation
for 24 h. Moisture content was determined as
percentage of initial film weight lost during drying and
was reported on wet basis.
Solubility in water was expressed as percentage of film
dry matter solubilized after 24 h immersion in distilled
water. A portion of the film (0.2 g dry matter) was weighed
and immersed in 40 mL of distilled water, containing
sodium azide (0.02% w/v) to prevent microbial growth at
20 C ± 2 with occasional agitation. After 24 h of immersion,
the sample was vacuum filtered through a preweighed
porous crucible. The crucible, containing any
undissolved pieces of film, was dried at 105 C for 24 h to
determine the weight of dry matter not dissolved in water.
The weight of the dry matter dissolved in water is equal to
the difference between the initial dry matter and the
remaining dry matter (not dissolved). This was expressed
as a percentage of the initial dry matter.