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

Abstract

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 × 108 cells/cm3, 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.

High-Strength Bio-Degradable Polymer Foams with Stable High Volume-Expansion Ratio Using Chain Extension and Green Supercritical Mixed-Gas Foaming

“…Under the optimal foaming condition, the VER value of the PBAT/PLA foam was 13.44, and the cell density was 4.08 × 10 8 cells/cm 3 . Because PBAT and PLA are incompatible systems and both have straight-chain structures and low melt strengths, the VER of unmodified PBAT/PLA is low [ 16 ]. Increasing the compatibility between PBAT and PLA is the key to improving the foaming performance of the blend [ 17 , 18 , 19 , 20 ].…”

Biodegradable highly porous interconnected poly(ε‐caprolactone)/poly(L‐lactide‐co‐ε‐caprolactone) scaffolds by supercritical foaming for small‐diameter vascular tissue engineering

“…It is notable that the melt strength can be improved efficiently by adding PLCL domains, which help the cell nucleation and cell growth during microcellular foaming process. 31,32 Cole-Cole curves are usually used for the description of viscoelastic of…”

Extruded polylactide bead foams using anhydrous supercritical CO2 extrusion foaming

“…Moreover, expanded PLA (EPLA) foam has received increased attention as a potential substitute for petroleum‐based foams (like EPS, and EPP) in the field of packaging, construction, thermal insulation, and so forth, due to its biodegradable nature 4,5 . Currently, various strategies including microcellular injection foaming, 6 autoclave foaming, 7 and extrusion foaming 8 have been developed to prepare polymer foams. In particular, bead foams have the special advantage of being able to form low‐density 3D complex components through steam‐chest molding 9–11 .…”