The Contrastive Study on the Influence of Different Cellulose Derivatives on Properties of Chitosan -Starch Complex Films

Cellulose derivatives sodium carboxymethyl cellulose (CMCNa) and methyl cellulose (MC) were added into the chitosan starch complex films separately. And the new complex films were obtained by cast line. Some properties of the complex films such as tensile strength, tensile elongation, water vapor transmission rate (WVTR), transparency, water absorption and the resistance to acids and bases were investigated. Through contrasting these properties with those of the films without cellulose derivatives, the influence of different cellulose derivatives on properties of chitosan starch complex films was studied. The results showed that the ensile strength of complex films decreased slowly and tensile elongation increased greatly as the CMCNa content increased. When the mass ratio of chitosan to CMCNa was 3:1, the tensile elongation was highest. As MC was blended into the complex films, the ensile strength of complex films increased greatly and tensile elongation changed very little. When the mass ratio of chitosan to MC was 2:1, the ensile strength was highest. The WVTR of complex films with CMCNa or MC was larger than that of the films without cellulose derivatives. The influence of CMCNa on WVTR was more significant than that of CM. The WVTR of complex film was highest as the mass ratio of chitosan to CMCNa was 4:1. The transparency and water absorption of complex films were decreased gradually while CMCNa or MC was added. And the change of the complex films with MC was more obvious than that of the films with CMCNa. Both of the complex films hydrolyzed slowly when they were dipped into diluted acid and they didn't hydrolyze when the solution was strong acid. When the complex films were immersed into alkali, they curled and didn't dissolve.