Abstract
The thermodynamic analysis of stress in one-component, one-phase elastic systems is reviewed, and it is suggested that the stress be evaluated in terms of entropy and enthalpy contributions. The analysis is then extended to two-component, two-phase systems, and the necessary equations are derived. By so doing, the temperature effect on swelling is taken into account. In addition, the basic hypotheses of the kinetic theory of rubber elasticity are shown to lead to conclusions which are thermodynamically impossible.