High‐Performance <scp>PLA</scp> Foam Blocks Prepared From Beads Modified by Chain Extension and Heterogeneous Nucleation

ABSTRACT Supercritical CO₂ foaming effectively forms a uniform cellular structure in polylactic acid (PLA) beads by utilizing the high diffusion rate and solubility of CO₂ in polymers. In this study, PLA beads are modified with a chain extender (CE) composed of ethylene and glycidyl methacrylate, while thermoplastic polyurethane (TPU) serves as a heterogeneous nucleating agent. After being foamed with supercritical CO, the modified PLA beads are compression molded into foam blocks. The volume expansion ratio of PLA/TPU/CE foams increases by 12.5‐fold, and the resulting foam blocks exhibit a high compressive modulus of 21 MPa. The enhanced compressive strength results from the synergistic effects of chain extension and heterogeneous nucleation, which enhance the material's cellular structure and internal crosslinking. This study offers an effective strategy to enhance the compressive properties of PLA foam blocks, expanding their applications in high‐performance industries. In addition, the use of eco‐friendly PLA and the potential for scalable production make this approach a promising alternative for sustainable materials.