2.3. Preparation of film-forming solutions(FFS) and casting of the films
CS-0 and CG FFS(2% w/v) were prepared by dissolving 2 g of copolymer in 100 mL of acetic acid(1% vlv) with magnetic stirring for 24 h 20+ 1 mL portions from each FFS were cast onto glass culture dishes with diameters of 16cm for the film-forming area, and dried at ambient condition. The obtained films(chitosan gallate concentration, 2.0 mg/cm2) were conditioned in an environmental chamber at 25 C and 50% relative humidity(RH) for 48 h before testing. 2.4. Rheological measurement of FFS