Environmentally friendly poly(butylene adipate-co-terephthalate) and CO2-based poly(propylene carbonate) biodegradable foams modified with short basalt fiber

As environmental pollution continues to rise, the demand for biodegradable materials, particularly biodegradable foams, is steadily increasing. We prepared high-density foam using extended poly(butylene adipate-co-terephthalate) (E-PBAT) and poly(propylene carbonate) (PPC), with basalt fiber (BF) serving as the filler, through an extrusion process. We conducted a detailed study to investigate the impact of PPC and BF content on the foaming of E-PBAT. We conducted a detailed study on how PPC and BF content influence the foaming of E-PBAT. This investigation revealed the formation of various phase morphologies within the composites, including “island-sea,” “quasi-co-continuous,” and “co-continuous” structures, which, in turn, altered the cellular morphology. The BF network played a crucial role as a structural backbone, enhancing the composite material's modulus, yield strength, and rheological complex viscosity (| η *|). Additionally, fiber networks can also serve as nucleation sites to promote cell nucleation and increase cell density. A higher cell density allows for more effective force transfer when the foam experiences external pressures, thereby enhancing its mechanical properties. We also summarized the mechanisms behind the changes in phase structure and fiber content on cell morphology. This summary provides valuable guidance for research on the extrusion foaming of biodegradable materials.