Biaxial Extension Studies Using Inflation of Sheets of Unimodal Model Networks

Measurements of uniaxial extension and compression were made on model poly(dimethylsiloxane) (PDMS) [−Si(CH 3 ) 2 −O−] x networks to examine the molecular theories of rubber elasticity. The stress-strain isotherms showed that the Flory-Erman theory of rubber elasticity is in good agreement with experimental data from extension to compression ( α −1 : 0.3–13), while the Mooney-Rivlin relation is useful only in a specific region of extension ratio ( α −1 : 0.3–0.8). The experimental results strongly support the theory of Flory-Erman, rather than those of phantom and affine networks. It is thus evident that the Flory-Erman theory of rubber elasticity is the more nearly correct.