Development of Biodegradable Films for Sustainable Agricultural Applications by Using Thermoplastic Potato Starch and PBAT

ABSTRACT The transition toward biodegradable agro‐films demands scalable formulations that match the performance of commodity plastics while avoiding toxic reagents. Here we report a 100% solvent‐free, twin‐screw‐extruded TPS‐PBAT blend simultaneously compatibilized with citric acid, glyceryl monostearate, and PEG‐400, a combination not previously explored. The ternary compatibilizer yielded a macroscopically uniform blend, doubled stiffness (Young's modulus (17.3 ± 0.9) MPa vs. (8.2 ± 0.4) MPa for TPS) and stabilized surface hydrophobicity (contact angle (63 ± 6) ° for ≥ 25 s) while preserving transparency and achieving > 99% UV‐B/C blocking. PBAT incorporation did not sacrifice biodegradability: both films reached 87% mineralization in industrial compost after 100 days and 62% in soil after 30 days, with no ecotoxicity toward tomato seedlings. Thermogravimetric analysis revealed partial TPS‐PBAT miscibility (~3 wt%) promoted by the compatibilizer trio, also confirmed by SEM. Urea‐loaded films released 80% of the nutrient in 13 days and then plateaued, demonstrating suitability as active, bio‐disintegrable seedling trays. This work closes the gap between laboratory‐scale TPS blends and industrial needs by introducing a green multicomponent compatibilization route, providing quantitative structure–property relationships, and validating field‐relevant functionality. The process relies on standard extruders, enabling straightforward global adoption in the agricultural plastic sector.