Functionalization of poly(butylene adipate‐co‐terephthalate) and its compatibilizing effect on PBAT/thermoplastic starch blends

Poly(butylene adipate‐co‐butylene terephthalate) (PBAT)/thermoplastic starch (TPS) blends were prepared by melt blending. However, the processability and practical application of PBAT/TPS blends are limited by their poor compatibility. To enhance the compatibility between PBAT and TPS, PBAT was functionalized by maleic anhydride (MA) to prepare PBAT‐MA, and then it was employed as a compatibilizer for PBAT/PBAT‐MA/TPS blends. The effects of PBAT‐MA on the tensile properties, rheological properties, morphology, and dynamic mechanics of PBAT/PBAT‐MA/TPS blends were studied in detail. Rheological results revealed that the interaction between PBAT‐MA and TPS enhanced the segment entanglement ability and improved the compatibility of the blends, which enhanced the tensile properties of the blends. Compared with the PBAT/PBAT‐MA/TPS (50/0/50) blend, the tensile strength of the PBAT/PBAT‐MA/TPS (40/10/50) blend increased from 9.2 to 15.8 MPa, and the elongation at break increased from 326.9% to 1017.6%. The dynamic mechanical results showed that the Tg of PBAT and TPS were close to each other after the addition of PBAT‐MA, which confirmed that the compatibility of the blend was improved. This study provides a feasible approach to preparing high‐performance and cost‐effective PBAT/PBAT‐MA/TPS blends while expanding the application prospects of PBAT in the packaging industry and agricultural film. Schematic description of the development of morphology for PBAT/PBAT‐MA/TPS blends.