Sustainable Hybrid Films Based on Ecovio, Sodium Nitrite, and Babassu Mesocarp Starch for Potential Packaging Applications

ABSTRACT Replacing conventional plastics in packaging requires biodegradable formulations that balance mechanical performance, thermal stability, and scalable melt processing. Despite growing interest in PBAT/PLA systems, few studies have concurrently incorporated an inorganic additive and a regionally sourced biomass derivative into an Ecovio matrix. This study developed flat‐die‐extruded Ecovio hybrid films containing sodium nitrite (NaNO 2 ; SN) and babassu starch (BS). It evaluated their effects on key structural, surface, thermal, and mechanical properties relevant to sustainable packaging. The results indicated preservation of the Ecovio chemical structure, increased intensity of C–O‐related bands upon BS incorporation, and no spectroscopic evidence of new chemical bonding associated with SN. Morphological analysis revealed a progressive increase in surface heterogeneity with higher BS content, while maintaining visually continuous films without macroscopic cracking. Water contact angle values shifted from hydrophobic (94.50°) to more hydrophilic behavior (76.96°), suggesting a combined effect of the SN/BS system on surface wettability. Thermal stability was comparable across formulations, with T dmax ranging from 398.38°C to 406.55°C, whereas the final residue varied broadly (4.69%–30.26%), suggesting composition‐dependent differences in residual mass formation. Relative to neat Ecovio, SN increased tensile strength and elongation at break (up to 23.72 MPa and 849.70%, respectively), whereas BS primarily enhanced tear strength (up to 25.33 N). Overall, the SN/BS hybrid films enabled tunable surface, thermal, and mechanical responses as a function of composition, offering a viable strategy for designing biodegradable packaging materials.