Biopolymer composite films based on κ-carrageenan and chitosan

Bioploymer composite films of κ-carrageenan and chitosan were prepared by co-dissolving κ-carrageenan and chitosan in several different organic acids. Tensile strength (TS), elongation (E), and water vapor permeability (WVP) were determined as a function of ascorbic acid added. Ascorbic acid tends to increase the properties of the films from all acids. Malic acid exhibited largest increase in tensile strength and elongation at 2% ascorbic acid and lactic acid in water vapor permeability. The strongest acid, citric acid exhibits overall the worst properties regardless of the amount of ascorbic acid. The ascorbic acid generally showed increase in TS and %E but little effect on the WVP except that from acetic acid. The results of the properties of the composite films indicated that there are interactions among the organic solvents, the plasticizer, κ-carrageenan, and chitosan in a complex manner.