Preparation and Properties of Biodegradable PBAT Composite Films Filled With ADR ‐4468 Modified Vinasse

ABSTRACT

Vinasse, characterized by abundant surface hydroxyl groups and strong polarity, exhibits poor interfacial compatibility with hydrophobic polymer materials, which severely impairs the comprehensive performance of the resultant composites. To boost the high‐value utilization of vinasse, this study grafted vinasse (Vin) with chain extender ADR‐4468 to prepare an epoxy‐functionalized modified vinasse powder, denoted as ADR‐4468‐Vin (A‐Vin). These epoxy groups acted as a molecular bridge to enhance interactions with biodegradable poly(butylene adipate‐co‐terephthalate) (PBAT). PBAT/A‐Vin composite films with A‐Vin loadings of 10%, 20%, 30%, and 40% (w/w) were then fabricated via extrusion granulation and blow molding. The films' structure, thermal stability, rheological properties, mechanical properties, water vapor and oxygen barrier performance, and biodegradability were systematically evaluated. Results showed that both pristine vinasse and A‐Vin reduced PBAT's thermal stability. Scanning electron microscope analysis confirmed that A‐Vin dispersed and compatibilized in the PBAT matrix far more effectively than pristine vinasse. Compared with the 20% pristine vinasse/PBAT film, the 20% A‐Vin/PBAT film showed a ~75% rise in tensile strength and 120% higher transverse elongation at break; its water vapor transmission coefficient also decreased by 33% relative to neat PBAT.