ABSTRACT
This chapter discusses what information on elastomer molecular structure can be extracted from the experiments in which small oscillating deformation is superimposed on a statically strained cross-linked rubber. The review of molecular theories of the loss modulus strain dependence is given. Derived dependence of the loss modulus on elastomer draw ratio contains three parameters: the loss modulus of the Gaussian chains, the fraction of the load-bearing strands and the extension ratio of the strands b in non-deformed state. Fitting these parameters to some published experimental data leads to conclusion that measurements of the strain dependencies of the loss modulus can be a new tool for studying polymer networks and especially load-bearing strands. Viscoelasticity strain dependences are measured from response of the strained elastomer to a small oscillating deformation. Numerous studies of equilibrium stress-strain dependences for cross-linked rubbers are summarized in monographs by L. R. G. Treloar and by Mark & Erman.
