Poly(ethylene glycol-ran-propylene glycol) lies within a family of thermo-separating polymers (commercialized as UCON ), thus they can be easily recovered from aqueous solution just heating above its lower critical solution temperature. Phase diagrams for UCON sulfate salt aqueous two-phase systems (ATPS) have been obtained experimentally in the temperature range 273.15 308.15 K by analysis of the equilibrium phases. The binodal curves and tie-lines have been correlated using suitable methods from the literature. The effect of temperature and the cation used in the sulfate salt (sodium, potassium, ammonium) are discussed. Temperature increases the heterogeneous region size while increases the polymer concentration in the polymer-rich phase and reduces the salt concentration in the salt-rich phase. This effect produces the phase inversion at high temperatures. The cation ability for phase splitting in these ATPS increases with the (more negative) Gibbs energy of hydration of the cation: Na+ greater than K+ greater than NH4 + .
Compounds
#
Formula
Name
1
K2O4S
potassium sulfate
2
H2O
water
Datasets
The table above is generated from the ThermoML associated json file (link above).
POMD and RXND refer to PureOrMixture and Reaction Datasets. The compound numbers are included in properties, variables, and phases, if specificied;
the numbers refer to the table of compounds on the left.