Construction of Superhydrophobic Poly (Lactic Acid)/Poly (Butylene Adipate‐Co‐Terephthalate) and Its Application in Yogurt Packing

ABSTRACT This study systematically investigated the enhancement of the hydrophobic properties of poly (lactic acid)/poly (butylene adipate‐co‐terephthalate) (PLLA/PBAT) composite films by incorporating hydrophobic SiO 2 nanoparticles at varying concentrations. Optimal performance was achieved with a 4% SiO 2 coating, which formed a densely textured surface layer, increasing the water contact angle (WCA) from 73.9° to 152.6°, indicating a transition to superhydrophobicity. However, excessive SiO 2 loading induced surface cracking, compromising structural integrity. Notably, the PLLA/PBAT/SiO 2 films exhibited excellent elongation at break values. Furthermore, owing to the enhanced hydrophobicity, the yogurt residue on the PLLA/PBAT/SiO 2 films was substantially reduced from 45.4% to 1.2% compared with that on commercial packaging materials. In addition, these films exhibited an oxygen permeability of 20 cm 3 /m 2 day and provided an effective ultraviolet (UV) barrier. Overall, these biodegradable superhydrophobic PLLA/PBAT/SiO 2 films demonstrate considerable potential for application in dairy packaging applications.