Well‐Controlled Microcellular Biodegradable PLA/Silk Composite Foams Using Supercritical CO2

PLA biodegradable composites reinforced with various silk fibroin powder contents (0, 1, 3, 5 and 7 wt.‐%) were prepared by solution processing technique using CH2Cl2 as solvent. After that the composites and virgin PLA were foamed by using supercritical CO2. The influence of silk contents on PLA/silk fibroin powder composite foams were investigated by using SEM, XRD and DSC. Compared with PLA foam, the composite foams exhibited a reduction in cell size and increase in cell density at high silk content. With an increase in saturation temperature and pressure, the cell size was increasing and both the cell density and foam density were decreased simultaneously. magnified image