The results showed that the produced chitosan has 6.85 % moisture content, 6.34 %
nitrogen content 0.1 % fat, 0.25 % ash, 86.7 % deacetylation and 230 cps viscosity. These
properties are similar to the properties of the commercial chitosan.
For production of biodegradable film, several parameters that could influence properties of
the film were optimized, including chitosan content, types and concentrations of organic acids,
volume of chitosan solution, chitosan: gelatin ratio, as well as types and required amount of
plasticizer.
The optimum conditions for preparing 20×25 cm
2
biodegradable chitosan film were
found to be 150 ml. of 1% chitosan-gelatin solution (1:1 chitosan: gelatin ratio) in 5% propionic
acid and 0.5% glycerol. The properties of the film were: tensile strength 70.385 N/ mm
2
;
elongation at break 13.463 mm/ mm; tearing resistance 616.7 mN; weight 2.243 mg/ piece; film
thickness 0.032 mm; and water va
por permeability 0.1564 x 10
-3
g.mm/ mm
2
hr mm Hg.
Comparable to mechanical properties of commercially available polyethylene film, the
produced chitosan-gelatin film was superior in tensile strength and tearing resistance, while
elongation at break and water vapor permeability were inferior.