Journal of Chemical and Engineering Data, Vol.57, No.4, 1112-1117, 2012
Equilibrium Phase Behavior of Poly(ethylene glycol) 4000 and Biodegradable Salts at Various Temperatures [(20, 30, and 40) degrees C]
Liquid-liquid equilibrium data for the PEG 4000 (poly(ethylene glycol)) + salt [sodium citrate (Na3C6H5O7), potassium citrate (K3C6H5O7), or ammonium citrate ((NH4)(3)C6H5O7)] + water systems have been determined experimentally at different temperatures. The effects of temperature on the binodal curves and tie-lines were studied, and it was observed that an increase of the temperature generally led to an increase of the two-phase area. The salting-out ability of the cations follows the ordering sodium citrate > potassium citrate > ammonium citrate. Finally, the Setschenow-type, Othmer-Tobias, and Bancroft equations have been successfully used to correlate the tie-line compositions.