Funtionalization of PEKK through the integration of iron microparticles

Kurzfassung

In this work, the integration of carbonyl iron microparticles in a PEKK 6000 matrix is investigated for electromagnetic functionalization purposes. Material degradation was observed during processing and so the mechanism of this effect is investigated with rheological and differential scanning calorimetry (DSC) measurements. Compounded iron filled Polyetherketonketon (PEKK) pellets are consolidated in a hot press to produce flat plates which are subsequently used to obtain samples for rheometry and DSC. To reproduce the process parameters, sample conditioning was done through an isothermal hold at 340 °C under air atmosphere. To observe the material degradation over time, the duration was set at 1 h. DSC measurements show that the inclusion of carbonyl iron particles substantially changes the thermal behavior of PEKK 6000. Full melting of the particle-filled compound, both in air and a protective atmosphere, removes both the crystallization and melting reactions from the polymer. Furthermore, glass transition temperature increases with each heating cycle in steps from 157 °C to 168 °C. This indicates a higher degree of cross-linking. Rheological measurements indicate that the transition between the viscous and elastic regimes for carbonyl iron-filled PEKK is strongly temperature dependent. This transition occurs after 52 min at 330 °C, whereas the same transition at 360 °C occurs after only 11 min. The driver behind this mechanism is proposed to be a thermally-induced radical reaction which leads to cross-linking of the polymer and is accelerated by the iron filler particles.