Eco-Friendly Starch-Nanocellulose Bio-Nanocomposite Films with Improved Structure-Property Interactions

Abstract

The development of sustainable and biodegradable substitutes has increased due to the growing environmental concerns surrounding petroleum-based polymers. In order to assess the impact of nanocellulose fiber loading on the physicochemical, structural, thermal, optical, and mechanical properties of starch-nanocellulose bio-nanocomposite films, these films were created and thoroughly characterized. Using a straightforward solution-casting technique, sulfuric acid hydrolysis was used to remove nanocellulose from filter paper and incorporate it into a thermoplastic starch matrix plasticized with glycerol. Water uptake, moisture absorption, solubility, tensile testing, X-ray diffraction (XRD), thermogravimetric analysis (TGA), and UV-vis spectroscopy were used to make and evaluate composite films containing 0, 5, 10, and 20 weight percent nanocellulose. Because of reduced free volume and increased hydrogen bonding within the matrix, the results demonstrate that increasing the nanocellulose content dramatically decreased water uptake and moisture absorption. The use of nanocellulose enhanced film continuity and decreased cracking, as demonstrated by morphological observations. TGA showed increased thermal stability at larger nanocellulose loadings, while XRD examination showed a steady rise in crystallinity from 32% for clean starch to 60% for the 20-weight percent nanocellulose composite. Although elongation at break reduced as a result of higher stiffness, mechanical testing revealed significant increases in tensile strength and Young's modulus with increasing nanocellulose concentration. These results show that starch-nanocellulose composites have enhanced strength, thermal resistance, and barrier qualities, underscoring their great promise as environmentally benign materials for biodegradable packaging and associated uses.