Examination of the Theories of Rubber Elasticity Using an Ideal Polymer Network

We evaluate the homogeneity of Tetra-PEG gel and examine the models predicting rubber elasticity. Infrared spectroscopy revealed the near absence of dangling chains. Concentration dependence of the number of elastically effective chains revealed the near absence of elastically ineffective loops and the validity of the phantom network model. These data suggest that Tetra-PEG gel is close to an ideal polymer network and that the phantom network model is the true model describing the contribution of the chemical cross-link to the rubber elasticity of a swollen polymer network.