Biodegradable polymeric microcellular foams by modified thermally induced phase separation method

Thermally induced phase separation (TIPS) for the fabrication of porous foams based on various biodegradable polymers of poly(L-lactic acid) and its copolymers with D-lactic acid and/or glycolic acid is presented. Diverse foam morphologies were obtained by systematically changing several parameters involved in the TIPS process, such as polymer type and concentration, coarsening conditions, solvent/nonsolvent composition, and the presence of an additive. The produced foams had microcellular structures with average pore diameters ranging from 1 to 30 mu m depending on the process parameters, which were characterized by scanning electron microscopy (SEM) and mercury intrusion porosimetry. Additionally, Pluronic F127 was used as an additive porogen to control the pore geometry and size. (C) 1999 Elsevier Science Ltd. All rights reserved.