WATER-SOLUBLE COPOLYMERS .31. EFFECTS OF MOLECULAR-PARAMETERS, SOLVATION, AND POLYMER ASSOCIATIONS ON DRAG REDUCTION PERFORMANCE

The relationships between drag reduction performance and polymer parameters including chemical structure, molecular weight, hydrodynamic volume, associations, and solvent nature were examined using synthetic water-soluble copolymers. Copolymer models were tailored to be systematically responsive to changes in electrolyte addition and included polyelectrolytes, polyampholytes, hydrophobically modified polymers, and uncharged, hydrophilic polymers. Commercial poly(ethylene oxide) (PEO) and copolymers of acrylamide with the comonomers sodium 3-(acrylamido)-3-methylbutanoate (NaAMB), sodium 2-(acrylamido)-2-methylpropanesulfonate (NaAMPS), [2-(acrylamido)-2-methylpropyl]dimethylammonium chloride (AMPDAC), and diacetone acrylamide (DAAM) synthesized in our laboratories were tested for drag reduction effectiveness using a rotating disk and a tube flow apparatus. Hydrodynamic volume as determined by viscometry and light scattering was monitored in deionized water and 0.514 M NaCl for particular compositions and molecular weights. Drag reduction performance was greatly affected by the nature of polymer/polymer and polymer/solvent interactions, generally increasing with hydrodynamic volume. Enhanced drag reduction behavior observed for the associating DAAM copolymers is proposed to be due to changes in water structuring in turbulent flow. © 1990, American Chemical Society. All rights reserved.