Fuente: Journal of applied polymer Lugar: RESEARCH ARTICLE The uniform dispersion of SA-ZnO nanoparticles in the PLA/EVA matrix, leading to enhanced UV-shielding, mechanical, barrier, and biodegradable properties for sustainable packaging.

ABSTRACT
High-performance and eco-friendly packaging materials are essential for replacing conventional plastics. In this study, polylactic acid (PLA) and ethylene-vinyl acetate (EVA) were blended to develop flexible and biodegradable films, functionally enhanced with stearic acid modified zinc oxide (ZnO) nanoparticles. The surface modification has been found to improve ZnO dispersion and interfacial compatibility within the PLA/EVA matrix, yielding a relatively uniform morphology and superior mechanical performance. The resulting composite films exhibited excellent UV-shielding efficiency, antimicrobial activity, and thermal stability while maintaining high transparency and flexibility. Comprehensive characterization using FTIR, SEM, XRD, UV–Vis spectroscopy, and tensile testing confirmed the functional improvement being induced by the nanodimension of stearic acid modified ZnO incorporation of nanoparticles and the enhanced functional behavior. Antibacterial assays against Staphylococcus aureus and antifungal assays against Rhizopus stolonifer highlighted strong inhibition zones, confirming the films' bio-protective potential. These findings highlight the synergistic role of EVA and surface-modified ZnO in reinforcing PLA matrices, enabling the successful development of UV-safe, antimicrobial, and biodegradable packaging films. The developed PLA/EVA–ZnO composites provide a sustainable alternative for active food and healthcare packaging, offering environmental compatibility combined with advanced protective functionality.