Impact of Organic and Inorganic Fillers on the Performance of Ternary Biodegradable Poly(Butylene Succinate‐Co‐Butylene Adipate), Poly(Butylene Adipate‐Co‐Terephthalate), and Poly(3‐Hydroxybutyrate‐Co‐3‐Hydroxyvalerate) Blends

ABSTRACT This study explores a ternary biodegradable blend of bio‐based poly(butylene succinate‐co‐adipate) (bio‐PBSA), poly(butylene adipate terephthalate) (PBAT), and poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) (PHBV). By blending with flexible bio‐PBSA and PBAT, the stiffness enhancement of PHBV makes this biodegradable polymer blend a promising candidate for packaging applications. The blends were processed by melt‐compounding via extrusion, followed by injection molding. The blend is enhanced with fillers including talc, kaolin clays, and soybean meal to evaluate and compare the effects of these fillers on the composite's performance. As an inorganic filler, kaolin outperformed talc and soybean meal, increasing Young's modulus by nearly 18%, impact strength by 20%, and elongation at break by approximately 21% compared with the ternary blend. Additionally, the addition of kaolin improved water vapor barrier properties by approximately 28%, primarily due to increased crystallinity. Rheological analysis also indicated a rise in complex viscosity, reflecting stronger adhesion between the matrix and talc compared to both organic and inorganic fillers. These findings highlight the potential of these composites to meet performance standards of traditional plastics, advancing the use of biodegradable materials in film packaging applications.