No abstract

A biodegradable blend foaming material of poly(butylene adipate-co-terephthalate) (PBAT)/poly(propylene carbonate) (PPC) was successfully prepared by chemical foaming agent and screw extrusion method. First, PBAT was modified by bis(tert-butyl dioxy isopropyl) benzene (BIBP) for chain extension, and then the extended PBAT (E-PBAT) was foamed with PPC using a twin (single) screw extruder. By analyzing the properties of the blends, we found that Young's modulus increased from 58.8 MPa of E-PBAT to 244.7 MPa of E-PBAT/PPC 50/50. The viscosity of the polymer has a critical influence on the formation of cells. Compared with neat PBAT (N-PBAT), the viscosity of E-PBAT increased by 3396 Pa•s and E-PBAT/PPC 50/50 increased by 8836 Pa•s. Meanwhile, the dynamic mechanical analysis (DMA) results showed that the storage modulus (E') at room temperature increased from 538 MPa to 1650 MPa. The various phase morphologies ("sea-island", "quasi-co-continuous" and "cocontinuous") and crystallinity of the blends affected the spread velocity of gas and further affected the foaming morphology in E-PBAT/PPC foam. Therefore, through the analysis of phase morphology and foaming mechanism, we concluded that the E-PBAT/PPC 70/30 component has both excellent strength and the best foaming performance.