Electrical failure in blends of chemically identical, soft thermoplastic elastomers with different elastic stiffness

Investigations on the effect of stiffness on breakdown strength in polymer materials are typically performed indirectly by variation of temperature. Here, the stiffness is varied directly using blends of chemically identical, physically crosslinking elastomers, thus avoiding possible temperature-induced variations in electric and ionic conductivity. Avoiding a chemically crosslinking system rules out variations due to crosslinkers or initiators. Measurements were carried out with a hemispherical indenter resting on a slab of the material with constant load. A theory recently proposed by Zhao and Suo was adapted to the experimental conditions and found to apply well, with no free fitting parameters.