Preparation of porous poly(L-lactic acid)-co-(trimethylene-carbonate) structures using supercritical CO₂ as antisolvent and as foaming agent

In this work, porous structures of poly(l-lactic acid)-co-(tri-methylene-carbonate) (PLLA-co-TMC) were successfully fabricated using two experimental methods, that is, using supercritical CO₂ as antisolvent and as foaming agent through the pressure induced phase separation technique. Considering the phase inversion method, the effect of the initial polymer concentration of the solution, pressure, and temperature on the morphology of the final porous structure (pore size, porosity, and cell density) was investigated. The L–L demixing process was suggested as the dominant mechanism for the phase separation and pore production. The temperature window, for which PLLA-co-TMC porous structures are successfully produced using the pressure induced phase separation technique, was determined at 150 and 210 bar. The effect of temperature on the final porous structure was investigated. POLYM. ENG. SCI., 57:1005–1015, 2017.