To investigate the new kinds of aqueous biphasic systems (ABS) produced by the addition of thermos-sensitive polymer to aqueous solution of ammonium salts, vapor – liquid equilibria (VLE) and liquid – liquid equilibria (LLE) behavior of aqueous ammonium salt (AS) – polymer solutions, were carried out for ternary systems including tetra methyl ammonium bromide (TMAB) + poly (propylene glycol) with an average molecular weight of 400 g.mol-1 (PPG400) + water, tetra ethyl ammonium bromide (TEAB) + PPG400 + water, TMAB + poly (ethylene glycol) with an average molecular weight of 400 g.mol-1 (PEG400) + water and TEAB + PEG400 + water. Our results show that, TMAB and TEAB in aqueous solution of PPG form ABS. The phase forming ability of the investigated AS increase with increasing the hydrophilicity of AS and follows the order TMAB > TEAB. In the VLE section, the water activity and constant water activity lines were obtained for aqueous solutions of TMAB and TEAB in the absence and presence of the polymers and inorganic salts at T = 298.15 K.
