Fused filament fabrication of polyetheretherketone/multiwalled carbon nanotube nanocomposites: the effect of thermally conductive nanometric filler on the printability and related properties

Fused filament fabrication is an additive layer manufacturing technique. It was extensively used at the beginning for the manufacturing of prototypes, and it has been adopted during the last few years for the manufacturing of fully functional components. Polyetheretherketone (PEEK) has been thoroughly investigated as a composite matrix because of its outstanding mechanical properties and thermal and chemical stability. This study is focused on PEEK nanocomposites with different amounts of carbon nanotubes (CNTs) (i.e. 3, 5, 10 wt%) produced in the form of a filament and successively 3D printed. The influence of the CNT presence on printability was studied and correlated to the nanocomposite feedstock thermal and microstructural properties, defining a substrate temperature processability window. Interestingly the addition of CNTs significantly limits the processability window due to the influence on the crystallization process and viscosity. Moreover, the thermal and mechanical properties of 3D printed bulk samples were investigated in view of the PEEK/CNT nanocomposite feedstock properties. © 2021 Society of Chemical Industry The mechanical and thermal properties of polyetheretherketone (PEEK) carbon nanotube (CNT) nanocomposite 3D printed parts are strongly affected by the filler presence due to their influence on crystallization, viscosity and thermal conductivity.