Cyclic Compression Testing of Three Elastomer Types—A Thermoplastic Vulcanizate Elastomer, a Liquid Silicone Rubber and Two Ethylene-Propylene-Diene Rubbers

Abstract

Thermoplastic elastomer vulcanizate (TPV) and liquid silicone rubber (LSR) are replacement candidates for ethylene-propylene-diene rubbers (EPDM), as they offer the possibility for two-component injection moulding. In this study, these material types were compared side by side in cyclic compression tests. The materials were also characterized to provide details on the formulations. Compared to the rubbers, the TPV had higher compression set (after a given cycle) and hysteresis loss, and a stronger Mullins effect. This is due to the thermoplastic matrix in the TPV. The LSR had lower compression set (after a given cycle) than the EPDM, but stronger Mullins effect and higher relative hysteresis loss. These differences between the LSR and the EPDM are likely due to differences in polymer network structure and type of filler. Methods for quantifying the Mullins effect are proposed, and correlations between a Mullins index and parameters such as compression set are discussed. The EPDMs showed a distinct trend in compression set, relative hysteresis loss and relaxed stress fraction vs. strain amplitude; these entities were almost independent of strain amplitude in the range 15–35%, while they increased in this range for the TPV and the LSR. The difference between the compression set values of the LSR and the EPDM decreased with increasing strain amplitude and increasing strain recovery time.

A Minimalistic, Synthetic Cell‐Inspired Metamaterial for Enabling Reversible Strain‐Stiffening

“…The cyclic test curves show hysteresis, which is a typical mechanical behavior of silicone-based material. [22] The strain-stiffening materials show a high degree of reversibility in the cyclic test with no evidence of plastic deformation. Due to an initial slip out of the sample of the clamps in the testing machine, only a very slight shift between the first and the other cycles is observed.…”

“…The cyclic test curves show hysteresis, which is a typical mechanical behavior of silicone‐based material. [ 22 ]…”

Effect of ionizing radiation on mechanical and damping properties of phenyl‐vinyl‐methyl‐polysiloxane elastomers cured with platinum

“…The most commonly used parameters are hysteresis loss or dissipated energy and relative hysteresis loss or damping factor 8,15 . The hysteresis loss is the difference between the integrals of the loading curve and the corresponding unloading curve 8 . This loss is also known as dissipated energy 15,16 or internal friction 17 .…”

“…The relative hysteresis loss or tan δ is obtained by dividing the hysteresis loss by the integral of the loading curve 8 . The hysteresis loss is also called the damping factor (tan δ) 17 .…”

“…The effect of ionizing radiation on the energy dissipation, stress softening, and damping properties of Pt-cured PVMQ elastomers was evaluated by cyclic uniaxial compression analyses by a UTM. 8,9 Figure 5 represents the stress-strain curves of 0-80 kGy irradiated Pt-PVMQ elastomers submitted to 10 uniaxial loading-unloading cycles with a strain σ = 50% (10 cycles of loading-unloading from zero stress up to the maximum strain down to zero stress) at 50 mm/ min compression and retraction rate.…”