Transforming invasive water hyacinth into nanocellulose-based biodegradable packaging films: Synthesis, comprehensive characterization, and sustainability assessment

Petroleum-based plastics are widely used in packaging, but their extensive use and poor biodegradability contribute significantly to persistent plastic waste and environmental pollution. This study aimed to valorize Eichhornia crassipes (water hyacinth), an invasive aquatic weed, into high-performance nanocellulose for biodegradable packaging films. Limited studies have investigated the direct incorporation of water hyacinth-derived nanocellulose in polyvinyl alcohol (PVA)-based films while integrating detailed performance characterization with a sustainability index and energy payback time analysis. Unlike prior works that relied on conventional cellulose sources or omitted comprehensive sustainability metrics, this study developed an optimized three-stage bleaching process using low-concentration chemicals, followed by sulfuric acid hydrolysis, to extract high-purity nanocellulose with the aim of reducing chemical and environmental burdens. The extracted nanocellulose exhibited fibril diameters of 100–430 nm, confirmed by SEM, and demonstrated strong chemical compatibility with PVA, glycerol, and acetic acid via FTIR analysis. The fabricated nanocellulose–PVA films showed 13.33% water absorption, which is substantially lower than unmodified cellulose films, around 62.99% and biodegradability of 21.05% weight loss after four weeks of soil burial. Mechanical testing recorded tensile stress of 7.319 ± 0.129 MPa (n = 2) and elongation at break of 81.48%, indicating a favorable strength–flexibility balance. By converting an invasive aquatic weed into value-added material, this work supports Sustainable Development Goals 9, 13, 14, and 15, while advancing circular economy goals and reducing marine plastic pollution.