Preparation and Properties of Corn Starch-Chitosan Composite Films Cross-linked by Maleic Anhydride

Starch-based films have been considered for many years as alternative polymeric materials for petroleum-based plastic-related industries due to their cheap, renewable and fully biodegradable properties and their potential barrier properties. However, compared to synthetic plastics, starch-based films suffer from their brittleness, susceptibility to aging, and high hydrophilicity. The absorption of water accelerates the degradation and recrystallization of starch and loses its mechanical properties.

In this paper, to improve the functional properties of starch-based films, chitin (CH) was prepared from shrimp shell powder and added to corn starch (CS) matrix. Before mixing, maleic anhydride (MA) was introduced as a cross-linking agent. The composite CS/MA-CH films were obtained by casting evaporation method. Mechanical property estimation showed that the addition of 0-7 wt% of MA-CH increased the tensile strength of the starch films from 3.89 MPa to 9.32 MPa. The elongation at break of the films decreased with the addition of MA-CH, but the decrease was significantly lower than that of previous studies. Morphological analysis showed that MA-CH was uniformly dispersed in the starch matrix and no cracks were found in the CS/MA-CH films.The incorporation of MA-CH reduced the water vapor permeability of the starch films. When the amount of MA-CH was lower than 5 wt%, the water absorption of the films was reduced.

Figure 1: ATR-FTIR spectra of chitin nanoparticles, starch membranes, S / CH1% membranes, S / CH3% membranes, etc

Figure secondary starch membrane, S / CH1000 fold amplification