A Novel Method for Preparing Microcellular PBAT/GNPs Foam with High Volume Expansion Ratio: Effect of Vacuum Foaming

Poly (butylene adipate-co-terephthalate) (PBAT) foam is a green and promising candidate to replace traditional oil-based polymer foam in the fields of buffer packaging, sporting goods and biomedicine, because of its admirable toughness, good resilience properties and excellent biodegradability. Herein, a novel methodology using the combination of autoclave foaming and vacuum foaming was reported to prepare chain-extended PBAT (CPBAT)/graphene nanosheets (GNPs) microcellular foams with high volume expansion ratio (VER). Compared with that prepared by single autoclave foaming, PBAT microcellular foams prepared by the combination of autoclave foaming and vacuum foaming possessed a higher VER up to 7.60, which had an increase of 324.58%. GNPs were used for the achievement of the filling modification of PBAT, which increased the cell density and compression properties of PBAT foams. When GNPs content were 2 phr, the compressive strength of CPBAT/GNPs2 foam reached 0.82 MPa. Above all, this research will provide a new facile approach to prepare biodegradable microcellular polymer foams with high VER.