Abstract: Poly(3-hydroxybutyrate-3-hydroxyhexanoate)/poly(lactic acid) (PHBH/PLA=80/20) blends were prepared via a melt blending method by using poly(ethylene oxide) (PEO), styrene-glycidyl methacrylate copolymer (REC), ethylene-co-glycidyl methacrylate (E-GMA), ethylenemethyl acrylateglycidyl methacrylate terpolymer (E-MA-GMA) and maleic-anhydride-grafted poly(lactic acid) (PLA-g-MAH) as compatiblizers. Mechanical properties, morphology and thermal properties of the blends were characterized by differential scanning calorimetry, dynamic thermomechanical analyzer, scanning electron microscopy and universal testing machine. The compatibility of PHBH/PLA was evaluated, and the effect of the compatibilizers on their compatibility was investigated. The results indicated that the effect of the compatibility was better with addition of REC or PLA-g-MAH, and the presence of REC or PLA-g-MAH reduced the difference between the glasstransition temperatures of PHBH and PLA and also reduced the particle size of dispersed phase with a more uniform distribution in the blends. Moreover, at a content of 4 wt % of REC or PLA-g-MAH,the impact strength increased by 43.8 % and 53.6 %,and the elongation at break increased by 100 % and 120 %, respectively.

Key words: poly(3-hydroxybutyrate-co-3-hydroxyhexanoate), poly(lactic acid), blend, compatibility, poly(lactic acid)-g-maleic anhydride copolymer