Mechanical behavior of amorphous PEEK in the rubbery state

Abstract

The mechanical behavior of amorphous poly(etheretherketone) (PEEK) was investigated just above the glass-transition temperature (Tg). In the rubbery state, the mobility of the macromolecular chains reveals a drop of mechanical properties with the onset of cold-crystallization as limit, as shown by dynamic-mechanical and thermal analysis. For an isothermal at 155°C, the onset of cold-crystallization begins after 40 minutes, this delay is long enough to perform static mechanical analysis. Thus, the understanding of the mechanical behavior was thoroughly investigated. From this study, different contributions are highlighted in the rubbery state: viscous and elastoplastic.