High‐Resilience and Anti‐Shrinkage PBAT Foams Enabled by TPU Elastomer Blending and Epoxy‐Based Chain Extender Compatibilization

Biodegradable poly(butylene adipate‐ co ‐terephthalate) (PBAT) foams are sustainable alternatives to petroleum‐based foams, yet their application is limited by poor resilience and severe post‐foaming shrinkage. Herein, we report a facile and effective strategy to fabricate high‐resilience, anti‐shrinkage PBAT foams by blending with thermoplastic polyurethane (TPU) elastomer and incorporating an epoxy‐based chain extender (CE) as a reactive compatibilizer. The epoxy groups of CE react with the terminal carboxyl and hydroxyl groups of both PBAT and TPU, generating in situ graft copolymers that significantly enhance interfacial adhesion. Rheological analysis confirms that the compatibilized blends exhibit effectively improved melt strength and elasticity. Benefiting from the combined effect of TPU toughening and CE compatibilization, the resultant PBAT/CE/TPU foam achieves a ball rebound of 52%, representing a 44.4% improvement over neat PBAT foam, and its 24 h shrinkage is remarkably reduced to just 5.3%. Scanning electron microscopy reveals a homogeneous cellular structure with well‐dispersed TPU domains embedded in the PBAT matrix. This work offers a promising route to high‐performance biodegradable foams for cushioning packaging, sports footwear, and automotive interiors, where resilience and dimensional stability are critically demanded.