Ductile polylactic acid-based blends derived from biomass

Polylactic acid (PLA) is a biodegradable plastic with good tensile strength and can be produced from biomass. But there are some defects, such as poor ductility, low barrier properties and poor-UV resistance, which may limit the application and development of PLA. To increase the ductility of PLA, bio-based poly(butylene succinate-butylene furandicarboxylate) (PBSF) was combined with PLA to obtain the blends with different PBSF contents. The blend’s compatibility, crystallinity, thermal, mechanical and rheological properties were determined. The addition of PBSF inhibited the cold crystallization of PLA. Wide-angle X-ray diffractometry (WAXD) showed that the tensile sample of PBSF was semi-crystalline, and the tensile samples of PLA and the blends were almost amorphous. A substantial shift in the stretching vibration of C=O was observed in the FTIR spectra, indicating that the oxygen atom in the furan ring improves the intermolecular interaction between PLA and PBSF. The fracture surfaces of the blends varied from typical brittle morphology to ductile morphology as a result of the addition of PBSF. At 180 °C, the complex viscosity decreased as the PBSF concentration increased. Tensile strength was 31.5 MPa and elongation-at-break was 390% when the amount of PBSF in the blend reached 30% (by weight). The findings demonstrate that PBSF can improve the ductility and processability of PLA.