A one-step method to manufacture biodegradable poly (butylene adipate-co-terephthalate) bead foam parts

Pollution caused by waste plastic, particularly from the foam packages, is increasingly worse, and utilizing biodegradable material is considered a promising solution to handle this environmental issue. Poly (butylene adipate-co-terephthalate) (PBAT) is a typical environment-friendly polymer due to the recognized biodegradability and excellent mechanical performance. However, there have been very few works preparing PBAT bead foams via the supercritical fluid foaming technology, and the related foaming behavior is still unclear. In this study, we foamed PBAT and PBAT-polylactide (PLA) beads using supercritical carbon dioxide (Sc-CO2) as a foaming agent, and the foaming behaviors of beads as well as the mechanical properties of bead foam parts manufactured by one-step foaming method were systematically investigated. The incorporation of PLA enhanced the mechanical properties of the composition. At the optimal foaming conditions, the expansion ratio and cell density of PBAT/PLA foam were 13.44 and 4.08 x 10(8) cells/cm(3), respectively. Benefitting from the uniform cell structure, the bead foam part showed excellent resilience and elasticity with adhesive strength of 0.57 MPa and compression strength of 1.05 MPa. Meanwhile, PBAT and PBAT-PLA foam parts had high surface quality and good interbead sintering properties. PBAT can be a promising substitute for traditional non-polymer foams for packaging, household, and automobile fields.