Abstract:Biodegradable polyester poly(butylenes adipate-co-terephthalate)(PBAT) was added to polylactic acid (PLA) matrix. Supercritical carbon dioxide microcellular foaming method was used to fabricate interconnected PLA microcellular with highly porosity. The results of cell structure show that cell size is minimum (11.56 μm), cell density is maximum (11.2×108 cm-3) and opening rate reaches up to 96.2% when the PBAT content is 20%. The viscosity of PLA/PBAT blends decrease because of addition of the PBAT content, which benefits to improve probability of cell wall connected. According to cell structure of foaming samples, cell opening mechanism of PLA/PBAT blends foaming samples was proposed, under the condition of proper foaming temperature, dispersion phase with lower melt viscosity in the blends is torn and ruptured during the cell growing process, while matrix with higher melt viscosity could be used as supporting skeleton to prevent cell collapse.