FORMATION OF POROUS POLYMERIC STRUCTURES BY THE POLYMERIZATION OF SINGLE-PHASE MICROEMULSIONS FORMULATED WITH METHYL-METHACRYLATE AND ACRYLIC-ACID

Phase behavior studies of microemulsions containing the monomers methyl methacrylate (MMA) and acrylic acid (AA), the cross-linking agent ethylene glycol dimethacrylate (EGDMA), and water, formed using sodium dodecyl sulfate (SDS) as the surfactant, and identical surfactant-free systems were carried out. The pseudo phase diagram for these systems was obtained. It was observed that certain compositions of MMA, AA, EDGMA, and water formed single-phase Winsor IV microemulsions even in the absence of the surfactant SDS. These single-phase mixtures exhibited physical characteristics which were similar to those of the single-phase microemulsions formed using the surfactant SDS. The properties of the single-phase domain of the phase diagram was studied by quasielastic light scattering, conductivity, and viscosity measurements. Considerable similarity in the physical properties of the systems containing the surfactant SDS and the surfactant-free compositions was observed. Polymerization of the single-phase microemulsions was carried out to yield porous solid materials and films having good mechanical stability. The microstructure of the polymers obtained was examined using scanning electron microscopy. This study reveals that polymerization of microemulsions containing monomers is a unique route for the formation of polymeric membranes without using an organic solvent.