| Abstract: | A theoretical analysis of the thermoelastic behavior of polymeric networks in swelling equilibrium with excess diluent, using both the kinetic theory of elasticity and the Flory-Huggins theory of mixing, is presented. Our calculations are restricted to the special case of diluents composed of a single constituent. The results are used to obtain the ratio of the energy component of the force fe to the total force f of rubber networks swollen in excess n-decane, and we find fe/f to be 0.17, which compares favorably with the value 0.18 reported for the unswollen network. Furthermore, fe/f is independent of elongation, in accordance with theory. The kinetic theory of elasticity is reasonably well obeyed in this highly swollen system although there remains a small contribution to the force from the C2 term of the Mooney-Rivlin phenomenological elasticity equation. It is not believed that this has an appreciable effect on fe/f. |
