Liquid–Liquid Equilibrium Data of Macromolecule + Ammonium Thiosulfate + Water Ternary Systems at 283.2, 298.2, and 313.2 K

Liquid–liquid equilibrium data were obtained for aqueous two-phase system (ATPS) composed of [poly­(ethylene oxide) (PEO1500), poly­(propylene oxide) (PPO425), poly­(ethylene oxide)11–poly­(propylene oxide)17–poly­(ethylene oxide)11 (L35), or poly­(propylene oxide)8–poly­(ethylene oxide)22–poly­(propylene oxide)8 (10R5)] + ammonium thiosulfate + water, at 283.2, 298.2, and 313.2 K. The consistencies of the all tie-line experimental compositions were improved by applying the Othmer–Tobias and Bancroft equations, resulting in linear correlation coefficients (R 2) ≥ 0.95. For all the ATPS, an increase in the temperature resulted in increases in the biphasic region and the tie-line slope, indicating that the phase separation process was entropically driven. Among the macromolecules studied, PPO425 produced the largest biphasic region, due to its greater hydrophobicity, followed by L35 ≈ 10R5 > PEO1500.