  Bioplastics are polymer plastics which are derived from renewable biomass
resources. In this study, bioplastic films based on two different
polysaccharides such as bitter cassava starch and chitosan extracted from crab
shells were produced by casting technique, using glycerol as plasticizer. The
purposes of this research are to characterize and to figure out the effect of
additional chitosan concentrations (0; 10; 20; 30; 50% by weight of starch) on
the physicochemical, mechanical and water barrier properties of bioplastic
films. The film's solubility in water (S), water absorption capacity (WAP),
water vapor permeability (WVP), tensile strength (TS), elongation at break (E),
Young's modulus (YM) and biodegradability were investigated. The possible
interactions between starch and chitosan molecules were evaluated by Fourier
transform infrared spectroscopy (FTIR). From the analysis, the incorporation of
the chitosan shows improved results on the water barrier properties of the
bioplastic films. Optimum solubility in water, water absorption capacity, and
water vapor permeability are obtained on the composition of starch/chitosan was
50/50. Actually, the addition of chitosan increased tensile strength, and
elongation at break. The characterization of optimum mechanical proprieties
also occurred on the 50/50 composition of cassava-starch and chitosan. At this
ratio, tensile strength obtained were 6,3000 MPa; and the elongation at break
were 62,8571%. It was found that cassava-starch/chitosan-based films have a
stable structure compared to native cassava-starch films.
