Structure and properties of active biodegradable films based on starch acetate, low-molecular chitosan and polyvinyl alcohol mixtures

The aim of this work was to propose new inexpensive compositions based on a mixture of starch acetate (AcSt), low molecular weight chitosan (LwCh), and polyvinyl alcohol (PVA) for preparation of active biodegradable films for various applications. To this end, the influence of biopolymer concentrations in the mixtures on the formed film structures was studied by the X-ray and SEM methods. The water-related, mechanical and UV-protective properties of the films were also evaluated. It was shown that among the studied samples, the films including 18-20 wt% PVA and 20-25 wt% LwCh had the most homogeneous structure and the best tensile strength and elongation at break. An increase in the LwCh concentration to 30 wt% resulted in films with solubility values close to those of edible systems. All the films were found to possess UV-protective properties. A seed germination test showed that the AcSt/LwCh/PVA systems promoted plant growth. Depending on the ratio of polymer components, such films can be recommended for use as food packaging, mulch coatings or pharmaceutical film materials.