[Retracted] Preparation and Supercritical CO₂ Foaming of Modified Nanocrystalline Cellulose Reinforced Polylactic Acid Bionanocomposites

Figure 8

Cell structure of foaming material under different foaming pressure (2 h, 110°C): (a) foaming pressure 12 MPa, (b) foaming pressure 14 MPa, (c) foaming pressure 16 MPa, and (d) foaming pressure 18 MPa.