A fused-deposition modeling (FDM) 3D-printed polyethylene terephthalate glycol (PETG)-sepiolite composite showed effective synergetic mechanical reinforcement in tensile testing compared to an injection-molded composite. The results showed that the addition of 3 phr sepiolite improved the tensile strength of 3D-printed PETG samples by 35.4%, while the tensile strength of injection-molded PETG samples was improved by 7.2%. To confirm these phenomena, FDM PETG-sepiolite composites were investigated by small-angle X-ray scattering to correlate the nanostructures of the composites with their mechanical strengths. The small-angle X-ray scattering data and transmission electron microscopy observations demonstrated that needle-shaped sepiolite particles were aligned in the printing direction. This fine oriented nanostructure formed during 3D printing created a synergistic effect that improved the material properties of the composite. These novel PETG-sepiolite composites with enhanced mechanical properties can be promising materials fabricated via FDM 3D printing.
Keywords: 3D printing; mechanical strength; nanoclay; nanocomposite; polyethylene terephthalate glycol; small-angle X-ray scattering.