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

Abstract

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.

Environmentally Friendly Melt-Processed Chitosan/Starch Composites Modified with PVA and Lignin

“…Chitosan-based films and coatings have been recently intensively studied [ 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 ]. Most of the research has been focused on evaluating different preparation conditions (including the processing method) and incorporation of additives to improve the properties of composites.…”

“…Recently, blends of chitosan/PVA, chitosan/starch, or chitosan/lignin have been greatly studied as promising materials for industrial applications [ 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 ]. Polymer blends of chitosan and PVA exhibited good thermal stability, unique morphology and reduced solubility in acid solution.…”

“…Polymer blending by mixing two natural biopolymers (chitosan and starch) with PVA was investigated in the following studies [ 16 , 17 , 18 ]. The infrared spectra confirmed the good compatibility of PVA with chitosan/starch composite [ 16 ].…”

“…Polymer blending by mixing two natural biopolymers (chitosan and starch) with PVA was investigated in the following studies [ 16 , 17 , 18 ]. The infrared spectra confirmed the good compatibility of PVA with chitosan/starch composite [ 16 ]. Additionally, several beneficial effects of PVA addition to the composite were observed: an increase of film flexibility and elongation at break [ 16 ], pore disappearance and smoothing of the surface [ 17 ], and improved mechanical and functional properties without the loss of biodegradability [ 18 ].…”

“…Taking into account the versatility of thermomechanical processing, we used this method to fabricate chitosan/starch composites with lignin and PVA. To the best of our knowledge, similar composites have been only obtained by conventional casting methods [ 16 , 17 , 18 ]. Moreover, every previous work describing thermomechanical-processed chitosan [ 19 , 20 ] was associated with its low content in the composite.…”