High Strain Rate Induced Phase Transition of Polymer

Abstract

In this study we report on the uniaxial compression stress-strain behavior of a representative polymer at a strain rate over which the material undergoes a viscoelastic phase transition. This means that the frequency of its segmental dynamics correspond to the loading frequency. This resonance condition results in large energy absorption, accounting for much of the enhanced impact resistance of polymer coated structures. The transition in the stress-strain behavior as strain rate increase is hard to characterize due to experimental limitations in accessing the full range of strain rates; herein a polymer with a higher Tg is used to overcome this issue. The temperature history of the specimen has been monitored during the experiment duration in order to quantify the temperature rise due to adiabatic conditions during loading. That is, we want to address the question of where does the energy go when a polymer-coated hard substrate is impact loaded.