Preparation and Characterization of Corn Starch-Based Composite Films Containing Corncob Cellulose and Cassia Oil

Starch-corncob cellulose-cassia oil (SCC) composite films are fabricated by a solution casting technique, using corn starch as substrate, corncob cellulose fibers as the reinforcing material, and cassia oil added as the bacteriostatic agent. The morphology, transmittance, thermal properties, permeability, and mechanical properties of the SCC composite films are studied. The SCC composite film with 2% w/w corncob cellulose and 0.2% v/w cassia oil show good properties. The surface of the SCC composite film is smooth, and the components are evenly mixed as shown by scanning electron microscopy images. Fourier transform infrared spectroscopic analysis also show that both cassia oil and corncob cellulose molecules successfully enter the starch matrix, and a stable starch-corncob cellulose cassia oil composite film is formed. Thermogravimetric analysis of the SCC composite film shows that the film has good thermal stability and good heat resistance. In the SCC composite film with 2% w/w corncob cellulose, tensile strength decreases the content of cassia oil increases, but elongation at break shows the trend of increasing initially and then decreasing. The SCC composite films have good mechanical properties and can keep fruit fresh, indicating that the composite film can be used as a good food packing material.