Development and characterisation of PLA-MWCNT filaments for multifunctional hybrid composites reinforced with continuous carbon fibre via 3D printing

The demand for advanced composite materials in high-performance applications, especially within the aerospace and automotive industries, has driven the development of innovative 3D printing thermoplastic matrix materials. This study introduces and characterises PLA-based filaments reinforced with Multi-Wall Carbon Nanotubes (MWCNT) at different concentrations to 3D print continuous carbon fibre-reinforced polymer composites (CFRPCs). The effect of nanofiller loading on the mechanical, thermal, hydrophobic, and morphological properties of the fabricated nanocomposite matrix filaments was systematically investigated. The hydrophobic properties of the PLA/MWCNT nanocomposite improved compared to pure PLA, while the tensile properties of the fabricated filaments showed significant enhancement at 0.5 and 2 wt% MWCNT loading. The thermal properties were also enhanced at 2 wt% MWCNT loading and the melt flow index test were used to assess the extrudability of the nanocomposite for fabricating filaments used in 3D printing. Filaments with 2 and 4 wt% MWCNT were 3D printed with continuos carbon fibre (CCF) to evaluate the composite's EMI shielding performance. The nanocomposites prepared herein can be characterised as multifunctional materials suitable for various industrial applications, such as sensor fabrication, health monitoring devices, etc.