Effect of Polyethyleneimine on CO₂ Foaming of Poly(L-Lactic Acid) Using a Twin-screw Extruder

초록

Using a twin-screw extruder to foam biodegradable polymers provides difficulties in terms of controlling the pore structure and characteristics. To produce biodegradable foam, carbon dioxide (CO2) and poly(ethylene imine) (PEI) were used in a twin-screw extrusion process to produce poly(lactic acid) (PLA) foam. PEI was used to facilitate the dispersion of CO2 inside the PLA and to promote the mixing of PLA with CO2 during the foaming process. A scanning electron microscope (SEM) was used to study how the shape of the resulting foam altered when the concentration of PEI varied to 1, 3, 5, and 10 wt%. The resulting foam had a closed-cell structure, and the presence of amine groups and their chemical composition were determined by FTIR and XPS analyses.