Thermoelasticity of networks in swelling equilibrium with mixed diluents: Specific polymer-diluent interactions

Thermoelasticity studies of poly(vinyl alcohol) networks swollen in aqueous glycol indicate that the effects of specific polymer-diluent interactions diminish at high swelling, much as in the situation of poly(vinyl alcohol) in pure water reported earlier. In 20% glycol, the ratio of the energy component f_e of the force to the total force f was found to be ?0.59 at high swelling. Swelling was controlled by the degree of network crosslinking. Evidence that f_e/f could be determined under the condition of a null thermal expansion coefficient was not obtained; in fact, the contrary was indicated.