<p>Polylactide (PLA)-based films were fabricated using a double bubble extrusion to enhance crystallinity, mechanical performance, and oxygen barrier properties. Blending PLA with poly(butylene adipate-co-terephthalate) (PBAT) and thermoplastic starch (TPS) influenced structural development during biaxial stretching. X-ray diffraction and differential scanning calorimetry revealed increased crystallinity, molecular orientation, and thermal stability. PBAT facilitated PLA crystallinity and improved ductility, resulting in reduced mechanical anisotropy and high elongation at break. TPS enhanced chain mobility and markedly reduced oxygen permeability. These results demonstrate that combining double bubble processing with targeted blending strategies provides a scalable route to high-performance biodegradable packaging films.</p> Graphical abstract <p></p>