Abstract:The poor toughness and stability of polylactic acid (PLA) limited its industrial production, so poly (butyric acid butyl glycol ester) (PBS) was introduced to improve properties of PLA in this paper. But due to the bad compatibility, a compatibilizer diphenylmethane diisocyanate (MDI) was used to improve the compatibility of the blending system. The experimental results show that the performance of PLA is greatly improved. According to the FT-IR, it is found that polyurethane is generated from the blending system. The SEM images show that the dispersion of the mixed system is improved. It can be seen from the torque diagram, the fluidity of the blending system is improved, and the plasticizing time of the blending system is 33 s and 53 s shorter than that of pure PLA/PBS and pure PLA, respectively. Through the mechanical property test, it is found that the elongation at break of the blend system is greatly improved, and the elongation at break is 1.57 times and 66 times higher than that of pure PLA/PBS and pure PLA, respectively.