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 T_g 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.