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 R2 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 R2 values were all greater than 0.9900, which proved that the Theta-Eyring-PC-SAFT model was universal.