We carry out uniaxial continuous and step stretching of various cross-linked polymer networks to demonstrate how characteristics of rupture during continuous stretching and delayed rupture after step stretching can be used to probe the structure of the emergent kinetic activation theory of bond dissociation (KATBD) for elastomeric failure. Based on delayed rupture experiments, we show that the network lifetime tntw, taken as the incubation time tdel-rupt for delayed rupture, depends on temperature in an Arrhenius like manner and is exponentially sensitive to the degree of network stretching (depicted by the step-stretch ratio λss). Rupture at λb during continuous stretching for a wide range of stretch rates takes place on time scales inversely proportional to the stretch rate. The elapsed time trupt at rupture is found to be comparable to tdel-rupt at various values of λb = λss in a wide range of temperature, affording the experimental basis for the premise of the KATBD. Having identified the hidden internal clock tntw, continuous stretching tests at different temperatures are performed to show the existence of a new time temperature equivalence (TTE): fast stretching at higher temperatures is equivalent to slow stretching at lower temperatures: different pairs of rate and temperature can produce the rupture at the same tensile strength and strain.
Siavoshani et al. (2026) studied this question.