AbstractThe thermoelastic behavior of poly(vinyl alcohol)–poly(acrylic acid) networks was evaluated in pure water and CaCl2solution. The ratiofe/fof the energy component of the force to the total force, evaluated without taking into account polymer–diluent specific interactions, ranged from −0.75 for networks swollen in pure water to −5.7 in 0.1MCaCl2. However, an analysis based on Flory's theory of polyelectrolyte gels yieldsfe/fconstant at −1.32 when specific interactions are accounted for. In addition, the variation of In (r2)0with CaCl2concentration is 2000 times that with water. In neither pure water nor CaCl2solution can specific interactions be