Improved bond strength, reduced porosity and enhanced mechanical properties of 3D-printed polyetherimide composites by carbon nanotubes

Fused deposition modelling (FDM) is one of the fastest-developing additive manufacturing approaches for printing polymers and composites. However, the existence of weak bond strength and high porosity is inevitable in 3D printed special engineering thermoplastics such as polyetherimide (PEI). In the present work, 3D printed carbon nanotube (CNT) reinforced PEI composites showed improved bond strength, reduced porosity and thus remarkably improved mechanical properties by introducing the CNTs. Specifically, the molten co-extrusion technique was employed to fabricate CNT/PEI composite filaments and then the FDM method was used to prepare CNT/PEI composite samples. Influences of CNT content on the tensile properties and microstructures were examined. Results showed that the incorporation of CNTs could improve the mechanical properties of 3D printed CNT/PEI composites obviously due to the dramatic enhancement of bond strength and the significant reduction of porosity of 3D-printed CNT/PEI composite samples by introducing the CNTs. Furthermore, the incorporation of CNTs combined with annealing is beneficial to further enhancing the mechanical performance and reducing the warping of 3D-printed PEI samples.

Automated summary

Fused deposition modelling (FDM) is a fast-developing method for 3D printing polymers and composites. This study focused on using carbon nanotubes (CNTs) to improve the mechanical properties of 3D printed polyetherimide (PEI) composites. The results showed that the incorporation of CNTs significantly enhanced the bond strength and reduced porosity of the composites. Additionally, combining CNTs with annealing further improved the mechanical performance and reduced warping of the printed samples.