In the study of their biodegradation behavior, film
of polymer sample (2:5 cm 2:5 cm with a thickness
of 0.2 mm) and solid mineral salts medium described
above were sterilized separately at 1.5 atm of steam,
and then placed in a Petri dish under a sterilized condition
and allowed to stand for 24 h. The appropriate
dilutions of the culture suspension of activated sludge
were spread onto solid mineral salts medium containing
polymer sample, and then incubated at 37 C in
various times. The initial weight of the polymer sample
was measured prior to the degradation tests. The
film specimens were periodically removed, washed
with distilled water and ethanol (95%), and dried
under vacuum for 4 h. Their weights were measured
after the film specimens were dried to constant
weight.
RESULTS AND