Effects of Butylene Adipate‐Lactate‐Butylene Terephthalate Copolyester on the Properties of PLA/PBS Blends

Polylactic acid (PLA) has good rigidity, transparency, biocompatibility, and biodegradability. It is expected to replace more traditional plastic products in the future. In this paper, a PLA/poly(butanediol succinate) (PBS) blend was prepared using poly(butanediol adipate‐lactate‐butanediol terephthalate) (PBLAT), which was synthesized in the laboratory, as a compatibilizer. The effects of PBLAT on the mechanical, rheological, and thermal properties of the blends were investigated. The scanning electron microscopy (SEM) results indicated that the addition of PBLAT effectively improved the compatibility of the PLA/PBS blend. When the PBLAT content was 3%, the interface compatibility between PLA and PBS was most favorable. Rheological test results showed that the addition of PBLAT enhanced the viscoelasticity of the PLA/PBS melt. When the PBLAT content was 1%, the elongation at break of the blend increased by 58%, and when the PBLAT content was 3%, the impact strength of the blend increased by 25%. The Vicat softening point of the blend increased from 72.9°C to 82.0°C, while the thermal stability remained essentially unchanged compared with the PLA/PBS blend. Therefore, it is of great significance to improve the compatibility between PLA and PBS to obtain PLA/PBS composites with excellent comprehensive properties and broaden their application range.