Study of the Mechanical and Biodegradable Properties of Cassava Starch/Chitosan/PVA Blends

Natural and synthetic polymers have been widely used for preparation of biodegradable materials. In this work, three different blends containing starch/ chitosan/PVA were prepared by varying the contents of cassava starch (MS blend), chitosan (CH blend) and PVA (PVA blend). The films were characterized through tensile/strength tests, infrared spectroscopy and biodegradation tests in soil. The PVA blends showed higher values of extension at break and lower loads, leading to more flexible materials when compared to MS and CH blends. The infrared spectra of all blends showed new bands that can be assigned to the carbonyl group (1716-1732 cm(-1)). Besides, changes in the intensity of other characteristic bands indicate that there are significant physical/chemical interactions among the components of the blends. All samples were shown to be biodegradable, leading to weight losses above 50% after 18 days of biodegradation in soil.