Lightweight and tough PVDF foams via high‐pressure foam injection molding with core‐back operation

Polyvinylidene fluoride (PVDF) foams prepared by batch foaming have been intensively studied, but it still remains a challenge to fabricate high-performance PVDF foams for structural applications. Herein, by adding polymethyl methacrylate (PMMA) as the minor component, the blend foams were successfully fabricated using supercritical carbon dioxide (CO2) as a green blowing agent via foam injection molding (FIM) with core-back operation. The added PMMA could reduce the crystal size of PVDF. Owing to fine cellular structure and small crystal sizes, the injection-molded blend microcellular foams exhibited superior mechanical properties. Especially, the elongation at break and specific breaking energy of the blend foam with 40% void fraction were separately increased by 184% and 297% compared to that of the PVDF foam. These findings revealed that the lightweight microcellular PVDF foams with improved toughness could be manufactured by the scale-up and efficient FIM technology, which showed a promising future in automotive and other structural applications.