Preparation, characterization, and electrical properties of PLA/rGO 3D printing composite filaments

Fused deposition modeling (FDM) 3D printing is characterized as a technology for manufacturing three-dimensional objects through the deposition of successive layers of molten material onto a build platform, based on a user-defined design. The development of non-conventional polymer-based filaments incorporating carbon-based semiconducting materials represents an open field of research in both academia and industry, with applications in emerging areas such as supercapacitors, photocatalysts, and sensors. This paper investigates the development of non-conventional filaments for FDM 3D printing based on polylactic acid (PLA) and reduced graphene oxide (rGO) nanoparticles, aiming to obtain electrically conductive properties for emerging applications in nanoelectronics. The composites were prepared by dispersing rGO in a PLA solution using chloroform as solvent, followed by controlled evaporation, oven drying, and hot melt extrusion of filaments with different rGO mass concentrations (0%–15% w w −1 ), all showing good reproducibility. Sample characterization was carried out using scanning electron microscopy, x-ray diffraction, differential scanning calorimetry, mechanical strength tests, and electrical resistivity measurements. The results revealed a typical electrical percolation behavior with a reduction in resistivity by 6 orders of magnitude (∼200 MΩ cm to ∼300 Ω cm), with a percolation threshold around 3.95% rGO. The rate of change in resistivity became less evident for the samples containing 9.1% or more of rGO, while filament processability was maintained up to 15% rGO, above which excessive stiffness was observed. Additional tests demonstrated the feasibility of printing three-dimensional structures with low electrical resistance, with potential for use in personalized functional devices.