Production of Biodegradable Packaging Material Based on Starch-kefiran-ZnO: Physical and Mechanical Characterization

In this study, biodegradable film based on starch-kefiran-ZnO was made by casting method. The produced films contain different content of nano ZnO (ZN) (1%, 3%, and 5% wt.). Also ZN dispersed by ultrasonic homogenizer and added to the starch-kefiran solution. Surface characteristics, thickness, moisture content, water vapor permeability and mechanical properties were investigated. In the images of water droplets, it was observed that the contact angle of starch-kefiran was 89.67 degrees. By increasing the amount of zinc oxide nanoparticles up to 1%, the contact angle increased significantly to 95.63 degrees, which means improving the surface properties and hydrophobicity. The water vapor permeability for starch-kefir film (×10−10 g m-1s−1Pa−1) was 3.12, which was increased to 2.03 (×10−10 g m-1s−1Pa−1) by increasing the concentration of zinc oxide up to 3%. Tensile strength and Young’s modulus of the specimens were increased by increasing ZN content up to 3%. On the other hand, elongation at break of the nanocomposites was decreased, simultaneously. It is obvious that, ZN was improved some of the packaging properties of the starch-kefiran film.