Journal of Applied Polymer Science · 2005 · 35 citations · 30 references
EngineeringChemical EngineeringMaterials SciencePolymer ChemistryPolymer EngineeringPolymer MaterialsBiodegradable PolymersMembrane CharacterizationMembrane EngineeringMembrane MaterialsPolymer MembranesPolymeric MembranesBiodegradable MembranesMembrane Morphology FormationPolymer Membrane MorphologyPolymer Membrane StructurePolymeric Membrane FabricationSolvent Effects On Membrane FormationSupercritical FlowSupercritical Fluids
Abstract There is increasing interest in the application of supercritical CO 2 (SCCO 2 ) in the preparation of polymer membranes. Membrane formation with SCCO 2 as a nonsolvent is analogous to the conventional immersion precipitation process using an organic nonsolvent. Polylactide membranes were prepared with SCCO 2 as the nonsolvent under different experimental conditions such as different polymer concentrations, different depressurization rates, and different nonsolvent compositions. The effects of these conditions on the cross‐sectional structure were investigated through scanning electron microscopy. In addition, solvent‐induced crystallization and CO 2 ‐induced crystallization were studied. The crystallinity of PLA membranes prepared with different solvents or at different pressures was characterized by wide‐angle X‐ray diffraction and differential scanning calorimetry. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 831–837, 2005
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