Investigation on the Drag Reduction by Interaction of Cationic Surfactant with Nonionic Polymer

To investigate the drag reduction effect of the interaction of surfactant with polymer, turbulent drag reduction tests with pure cationic surfactant CTAC and nonionic polymer PAM and their mixed solutions were carried out. As nonionic polymer PAM with different concentrations were added into the CTAC solution, the critical temperatures for drag reduction of the mixed solutions were all the same, but below the one for the corresponding pure CTAC solution. And the drag reduction tendency of the mixed solution decreased more slowly when exceeding the critical temperature. Both the drag reduction stable zones of the mixed solutions and the friction coefficient in the stable zones were basically the same as that of the pure CTAC solution at each temperature. The mixed solution's drag reduction ability was good even in the drag reduction damage zones, and this ability could be enhanced with the increase of PAM concentrations. Surfactant micelles were attached to the polymer chains, forming stable mixed network structures because of the dense inner cross-linkings. Turbulent drag reduction phenomena of the mixed solutions can be well explained using the mixed network structure model.