Description:
<jats:title>Abstract</jats:title><jats:p>The thermodynamic functions of water sorption by polymethylstyrenesulphonic acid and its sodium salt have been determined by means of calorimetric and isopiestic measurements. The plots of these functions versus water content are presented for the range from 0 to 12 moles of water per equivalent of polyelectrolyte. A qualitative interpretation of the form of these plots is given and, at the same time, a comparison is made with the same plots of the corresponding cross‐linked analogues of the polyelectrolytes mentioned above, i.e., the polystyrenesulphonic acid resins in the hydrogen and sodium states. It is found that the differences between the values of these functions for the linear and cross‐linked polyelectrolytes are rather small and that, contrary to what might be expected, these values for the linear polyelectrolytes are closer to those of the highly cross‐linked resins.</jats:p>