Abstract

Liquid-liquid equilibrium data for poly vinyl pyrrolidone (PVP) K30+K2HPO4+H2O system were measured at 298.15 K and different pH values (7.54, 8.05, and 9.47). A binodal curve was fitted to the Merchuk equation and the tie line compositions were fitted to both the Othmer-Tobias and Bancroft equations. The refractive indices and densities of several homogeneous binary and ternary solutions used for calibration were also measured within a range of 0–30 mass% of PVP and 0–50 mass% of K2HPO4. Then, the viscosities, densities, electrical conductivities, and refractive indices of binary (PVP K30+water; potassium phosphate+water) and ternary (PVP K30+potassium phosphate+water) systems were measured and correlated at different pH values. The density data showed a linear variation of the polymer and salt mass fractions. The viscosity data of PVP K30 solutions were correlated as a function of the mass fractions by using a nonlinear equation. The effects of the tie line lengths on the densities and viscosities of the aqueous two-phase systems were represented. Also, the modified UNIFAC-NRF is used to calculate the phase equilibria of the mention system. The fitted binary interaction parameters of the model were reported.

Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call