The interactions of the hydrophobically modified acrylamide copolymer (PDAM) widi anionic surfactant sodium dodecyl sulfate (SDS) in aqueous solution have been studied by viscometry, fluorescence probe technique and H NMR relaxation and self-diffusion measurement. The polymer, which contains a small amount of dendritic poiyether block, exhibits a larger hydrophobic effect and easily interacts with SDS, to form a mixed micelle-like aggregate within the concentration region far below the critical micelle concentration ( cmc). With the addition of SDS to the copolymer solution, the viscosity of the polymer solution changed dramatically and a more pronounced maximum appeared at the lower surfactant concentration. Fluorescence and 'H NMR results indicated that these complex behaviors can be attributed to the different structures of PDAM/SDS aggregates formed in the different SDS concentration regions.

Key words: POLYETHER, POLYACRYLAMIDE, ANIONIC SURFACTANTS, VISCOSITY, ASSOCIATION, AGGREGALES, 1HNMR, SDS, INTERACTIONS