Coupling between thermal ageing/degradation and creep behavior of PEKK and C/PEKK composites above the glass transition temperature

Abstract The present work aims at investigating the coupling between thermal ageing/degradation and creep behavior of PEKK and C/PEKK composites at 200°C, above the glass transition temperature (which is close to 160°C). Ageing tests were carried out at 200°C, under 5 bar of oxygen conditioned atmosphere. DSC scans and DMA tests were carried out. Tests results discussion were supported by indentation tests and image analysis of the aged specimen cross-section. Coupled oxidation-thermomechanical-creep tests were carried out on C/PEKK samples at 200°C under a 5 bar O2 environment. The resulting strain response was compared to creep tests carried out on C/PEKK samples at 200°C under air at similar creep stress. Such comparison allowed to investigate the presence of degradation phenomena in C/PEKK samples. The analysis of X-rays µ-tomography scans allowed investigating the possible occurrence of degradation, and to discriminate between pure thermal and thermomechanical coupling with degradation phenomena..