PHOTOPHYSICAL AND RHEOLOGICAL STUDIES OF AMPHIPHILIC POLYELECTROLYTES - CORRELATION OF POLYMER MICROSTRUCTURE WITH ASSOCIATIVE-THICKENING BEHAVIOR

The synthesis and aqueous solution properties of two hydrophobically modified polyelectrolyte systems are examined. Micellar polymerization was used provide terpolymers of similar bulk composition but with varied hydrophobic microstructures via alteration of the surfactant to hydrophobic comonomer molar ratio (SMR). This synthetic parameter dictates the initial number of hydrophobic monomers per micelle, which ultimately controls the co- or terpolymer microstructure and resultant solution properties. The first system utilizes the fluorescent N-[(1-pyrenylsulfonamido)ethyl]acrylamide (APS) monomer as the hydrophobic component to provide direct evidence of microstructural placement. The second system utilizing N-(4-decyl)phenyacrylamide (DPAM) exhibits associative thickening behavior which is dependent on the SMR used in polymerization. These terpolymer systems indicate how variation of the [SDS] to [hydrophobic comonomer], even over a narrow range, can provide polymer systems with significantly different microstructural characteristics and associative properties.