Thermodynamic modeling procedure for modeling viscosity of polymer solutions

In this work, the density and viscosity of five commonly used polymer aqueous solutions with a concentration range of 1–35 wt%, including polyvinylpyrrolidone (PVP) K25, PVP K30, PVP K90, polyethylene glycol (PEG) 6000 and hydroxypropyl methyl cellulose (HPMC), were determined at 293.15–313.15 K. The viscosity data were modeled by Simplified-Eyring-NRTL, Eyring-PC-SAFT and Simplified-Eyring-PC-SAFT models. Based on the correlation between the viscosity and the surface area fraction of solute and solvent, the Theta-Eyring-PC-SAFT model was proposed. The model had the best fitting effect on the viscosity data of PEG, PVP K25, PVP K30, PVP K90 and HPMC, and the correlation coefficients R 2 were 0.9998, 0.9988, 0.9995, 0.9999 and 0.9999, respectively. In addition, the viscosity data of other systems in the literatures were also fitted, and the R 2 values were all greater than 0.9900, which proved that the Theta-Eyring-PC-SAFT model was universal.