Preparation of UV-protective starch/kefiran/ZnO nanocomposite as a packaging film: Characterization

In this study, UV-protective biodegradable nanocomposite films composed of starch/kefiran/ZnO were developed and characterized as a function of the content of nano ZnO (ZN) (1%, 3%, and 5% wt.). The packaging properties of the nanocomposite films i.e. WVP, moisture sensibility, mechanical properties, and UV-protection were measured. SEM and TGA/DSC analyses were used to investigate the microstructures and thermal properties of the films. Mechanical analysis demonstrated that by increasing ZN content up to 3%, the tensile strength and Young's modulus of the specimens were increased. Elongation at break of the nanocomposites was decreased. The UV-vis spectrum confirmed the UV-protective property of the films. The thermal properties of the samples indicate that Tm increased by increasing ZN content. Also, decomposition temperature was enhanced by nanoparticle application. SEM micrographs confirmed that aggregation of the ZN particles increased with increasing ZN content.