Water-soluble copolymers. 31. Effects of molecular parameters, solvation, and polymer associations on drag reduction performance

Abstract

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(ethy1ene 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. IntroductionThe reduction of drag in turbulent flow produced by addition of small concentrations of high molecular weight polymers has been studied for over 40 years.' Studies of polymers of varying structures have shown that drag reduc-

Biodegradability enhancement of purified terephthalic acid wastewater by coagulation–flocculation process as pretreatment

“…Coagulation and flocculation method is widely used for treating majority of industrial wastewaters [37,38]. Terephthalic acid is the main component in an alkali decrement wastewater, which was efficiently removed using ferric chloride in a high pH solution.…”

Turbulent Drag Reduction with Polymers in Rotating Disk Flow

“…DR efficiency varies with polymer concentration, molecular weight, and chain length, whereas the coil dimension is considered to be as important as molecular weight [68,69]. McCormick et al [69] suggested that good DR can be achieved by low-molecular-weight polymers if their concentrations are high enough (Figure 14).…”

Polymer and Surfactant Drag Reduction in Turbulent Flows

“…The biodegradation resistance of these copolymers is enhanced because the altered molecular structures inhibit enzyme attack [Singh, 1995]. McCormick et al also reported that copolymers of PAM with polyelectrolytes showed better DR efficiency than that of PAM alone [McCormick et al, 1990;Mumick and McCormick, 1992]. McCormick et al also reported that copolymers of PAM with polyelectrolytes showed better DR efficiency than that of PAM alone [McCormick et al, 1990;Mumick and McCormick, 1992].…”