Study On Preparation And Properties Of The Nature Polysaccharide Films

Starch, a kind of natural polysaccharides, is environment-friendly material. Because of its good biodegradability, starch has been a major focus of interest in packaging materials.Biodegradable films were developed from oxidized starch (Ost) with different glycerol contents as plasticizer. After the exploring of the preparation method, oxidized starch (Ost) and its composite films were prepared successfully by casting method, and characterized by mechanical properties, solubility in water, oil resistance, FT-IR, X-ray diffraction, SEM etc. Mechanical properties of these films indicated that the film with 19.4wt% glycerol exhibited the desirable mechanical properties, and the 20wt% addition of starch acetate improved the mechanical propertites of films. X-ray diffraction pattern showed that the increase of glycerol content decreased the crystallinity of films, and storage time and storage condition had certain effect on the crystallinity of films. Ost films were transparent and flexible, and showed good anti-crosslinking ability in saturated formaldehyde vapor. Oil resistance showed that the films had excellent oil resistance. Acid or alkali resistance of Ost films was measured, and the results showed that the films had good acid resistance but poor alkali resistance.