Enhancing the Antishrinkage and Mechanical Performances of the PBAT/PVA Foam for Environment-Friendly Packaging

Currently, as a biodegradable polyester, poly(butylene adipate-co-terephthalate) (PBAT) and its foamed part are widely used in the packaging field due to its excellent ductility and heat resistance. However, the low-melt strength and poor shrinkage resistance of PBAT influence the foaming behavior, decrease the mechanical performance, and weaken the shape stability, thus restricting its regular use. Herein, an environment-friendly and water-soluble poly(vinyl alcohol) (PVA), with superior mechanical properties and low cost, was introduced to fabricate the blend foam via combining thermal processing and supercritical carbon dioxide (scCO2) foaming technologies. The effects of PVA content on the phase morphology and rheological behavior of the blend, as well as the cell structure and mechanical properties of the PBAT/PVA blend foam, were deeply investigated. Additionally, the incorpation of PVA and the porous structure of blend foam contributed to the soil consumption capacity, owing to PVA’s better water solubility and foam’s higher specific surface area. The achieved PBAT/PVA foam demonstrated a higher specific compressive strength of 1.05 × 104 N·m/kg, a higher mass loss ratio of 28.2%, and a lower volume shrinkage ratio of 0.7%, providing valuable insights for expanding PBAT applications and addressing disposable foam plastic pollution.