The effect of CaCl2 on the interaction between hydrolyzed polyacrylamide and sodium stearate: Rheological property study

The effect of CaCl2 on the interaction between partially hydrolyzed polyacrylamide (HPAM) and sodium stearate (C17H35COONa) was investigated by steady-flow and oscillatory experiments at 25 °C and 70 °C, respectively. The results of steady-flow measurement indicate that the viscosities of both HPAM and HPAM/C17H35COONa systems decrease obviously with the addition of CaCl2, and show shear-thinning property at higher shear rate. But the viscosity of the system with C17H35COONa is higher than that of HPAM solution at same CaCl2 concentration. In oscillatory experiment, both HPAM and HPAM/C17H35COONa systems show elastic behaviors and their viscoelastic behaviors depend strongly on the CaCl2 concentration. And the capability that HPAM/C17H35COONa system endures higher concentration CaCl2 at higher temperature is better than that of HPAM system because of the formation of complex between HPAM and C17H35COONa.