Multi-functional polyamide 12 (PA12)/ multiwall carbon nanotube 3D printed nanocomposites with enhanced mechanical and electrical properties

Inducing electrical properties in thermoplastic materials and enhancing their mechanical properties with the addition of nanofiller in Fused Filament Fabrication (FFF) is the main purpose of the study. Multiwall carbon nanotubes (MWCNT) at different weight percentage (wt.%) loadings (0.1%, 0.5%, 1.0%, 2.5%, 5.0%, 10.0%) were incorporated into the Polyamide 12 (PA12) matrix. Melt mixing followed by filament extrusion was applied. Filaments were employed to 3D print specimens. A thorough study on the electrically Conductive Polymeric Composites (CPCs) electrical percolation threshold was carried out. Mechanical and thermomechanical response investigations were also conducted. Scanning Electron Microscopy (SEM) was employed to study the morphology of the 3D printed samples. The results showed a mechanical and thermomechanical properties enhancement for 5.0 wt.% filler’s ratio. The electrical conductivity increased by increasing the filler loading. The 10% wt.% PA12/MWCNT nanocomposite additionally exhibited an electrothermal Joule-heating behavior. The antibacterial behavior was also tested with the agar well diffusion screening method, for gram-negative Escherichia coli (E. coli) and gram-positive Staphylococcus aureus (S. aureus). A mild antimicrobial performance was observed. It can be concluded that the multi-functional PA12/MWCNT 3D printed lightweight CPCs developed herein could be applied in various applications, e.g. joule-heating devices, flexible conductors, and anti-static enclosures.