Structure-tunable polyether block amide/polylactic acid foams with shape memory performance using supercritical CO2 foaming

Lightweight and structure-tunable shape memory polyether block amide (PEBA)/polylactic acid (PLA) foams were prepared using an efficient, green microcellular foaming technology. PLA is conducive to increasing the shape fixing ratio of PEBA/PLA, whereas PEBA is favorable for enhancing the shape recovery ratio. The shape memory performance and mechanical properties of PEBA/PLA foams can be modified by adjusting the expansion ratio and cellular structure. When the blend ratio of PEBA/PLA is 80/20, the expansion ratio above 6.4 can enhance both the shape fixing ratio and the shape recovery ratio. A cell size of 23.3-43.6 mu m significantly improves the shape fixing ratio, while a cell size of 7.0-10.4 mu m is advantageous for enhancing the shape recovery ratio. PEBA/PLA foams have a density of 0.17 g/cm3 and shape memory properties with a shape fixing ratio of 87.2% and shape recovery ratio of 90.5%.