Thermodynamic Parameters for the Protonation of Poly(allylamine) in concentrated LiCl(aq) and NaCl(aq)

The acid-base properties of poly(allylamine) (MW ) 15 kDa) were determined by potentiometry and calorimetry in aqueous solutions at t ) 25 °C. Potentiometric measurements were carried out in a wide range of ionic strengths (0.1 e I/molâL-1 e 5.0) in NaCl(aq) and LiCl(aq), while enthalpy changes for the protonation of poly(allylamine) were determined by calorimetry in the same ionic strength range but only in NaCl(aq). Analysis of the experimental data was carried out using two different models: the first based on a modified Henderson-Hasselbalch two parameter equation and the second on the three parameter equation proposed by Ho¨gfeldt. Protonation constants are given for both models and io…