The structure and properties of a starch-based biodegradable film

A starch-based biodegradable film, with a nano silicon dioxide (nano-SiO2) content, was prepared by the coating method in this paper, through which its physical and biodegradable properties were studied. The structure of the film was characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), differential scanning calorimeter (DSC), and scanning electron microscopy (SEM). As compared to a film without nano-SiO2, the crystallinity of the film was decreased from 41.2% to 32.9%; the tensile strength, breaking elongation, and transmittance were increased by 79.4%, 18%, and 15%, respectively; and the water absorption was decreased by 70%. A hydrogen bond was formed in nano-SiO2 and starch/polyvinyl alcohol (PVA), and intermolecular hydrogen bonding of the starch was decreased at the addition of nano-SiO2. Meanwhile, the chemical bond C–O–Si was also formed in nano-SiO2/starch/PVA hybrid materials; therefore, the miscibility and compatibility between starch and PVA were increased.