Preparation of <scp>PBAT</scp>/<scp>PLA</scp> Blend Microporous Foam With Excellent Resilience and Cushioning Properties by <scp>scCO₂</scp> Technology Through Improving Compatibility

ABSTRACT The lightweight microcellular foams of polybutylene adipate terephthalate/polylactic acid (PBAT/PLA) with high mechanical strength and excellent resilience and buffering properties were reported using supercritical CO 2 foaming technology. The effects of an epoxy chain extender (ST‐CE37B) on the mechanical properties, rheological properties, and dispersion morphology of PBAT/PLA blends were studied. The results showed that ST‐CE37B can act as compatibilizers and the PBAT/PLA blend with 0.5 phr ST‐CE37B exhibited the highest tensile strength (22 MPa). The PBAT/PLA foam with 0.7 phr ST‐CE37B, expansion ratio of 8.0 displayed the minor cell diameter (19.3 μm) and highest cell density (5.44 × 107 cells/cm 3 ), the compressive strength was greater than that of pure PBAT/PLA foam, and the permanent strain was less than 15%. Therefore, compared with other foams, it can withstand larger stress according to the cushioning performance. In addition, this work also discussed the compression rebound performance (resilience) test of foam with the same blending sample, the same cell density, and different cell structures. It was found that foam with a larger cell size (49.2 μ m) showed lower permanent deformation and energy loss coefficient. This study provides a feasible method for preparing high microporous PBAT/PLA foam, expands the application range of biodegradable foam, and has research significance.