Effect of swelling and deswelling on the elasticity of polymer networks in the dilute to semi-dilute region

The Obukhov model is known as the model describing the dependence of the elastic modulus of polymer networks on the concentration and solvent class. In the Obukhov model, the Panyukov model, which assumed the Hooke's law of elasticity, was adopted for describing the elastic energy of a network strand. In this study, we for the first time extended both models from the semi-dilute to concentrated region to the dilute to semi-dilute region. To evaluate the extended model, we used Tetra-PEG gel, which has near-ideal network structure, as a model system. The experimental results are well described by the extended model. It is strongly suggested that the Panyukov model and the Obukhov model are valid in dilute to semi-dilute good solvent systems.