Transesterification effects on miscibility polycarbonate/poly(butylene adipate-co-terephthalate) blends

The effects of transesterification on the miscibility of polycarbonate (PC)/poly(butylenes adipate-co-terephthalate) (PBAT) blends were investigated. The PC/PBAT blends were prepared with a twin-screw extruder, and then annealed at 260 °C for 5 h to trigger the transesterification reaction. ¹H NMR, FT-IR, and WAXD results indicated that transesterification in the annealed PC/PBAT blends took place and led to the formation of a random copolymer structure. Because the copolymer serves as a compatibilizer, the PC/PBAT blends showed improved miscibility, as confirmed by FE-SEM and DMA analyses. The compatible morphology achieved through transesterification ultimately increased the thermal stability of the PC/PBAT blends. We could thus conclude that transesterification in PC/PBAT blends forms a random copolymer which plays an important role as a compatibilizer and consequently improves the miscibility as well as the thermal properties of the blends.