Evolution of mechanical properties of aged poly(ether ketone ketone) explained by a microstructural approach

In this work, the thermo-oxidative behavior of PEKK films (~50 µm thick) in solid state were investigated. Since mechanical properties samples, especially strain at break, are clearly affected after long ageing time, modifications structure have been monitored molecular and macromolecular scales using different techniques such as gel permeation chromatography, X-Ray scattering, differential scanning calorimetry, dynamic analysis. If embrittlement specimens seems to appear due a predominant branching/cross-linking phenomenon occurring scale, crystalline morphology is also slightly modified chain scission mechanism simultaneously.