Effect of molecular weight on mechanical properties and microstructure of 3D printed poly(ether ether ketone)

Fused deposition modeling (FDM) has been successfully applied to the manufacturing of poly(ether ether ketone) (PEEK) special engineering plastics. However, due to the unavoidable defects caused by FDM technology and the high melt viscosity of PEEK, 3D printed PEEK parts have poor mechanical properties. In this study, the mechanical properties and microstructure of PEEK printed with different nozzle temperatures and having various molecular weights were researched in detail. The results showed that PEEK-033G with medium molecular weight had good fluidity. With a nozzle temperature of 410 degrees C and using a high-temperature chamber 3D printing system, the defects of 3D printed PEEK-033G were reduced significantly, and the tensile strength and flexural strength could reach 96 and 115 MPa, which is close to the performance obtained using injection molding. In addition, the tensile strength in the Z-axis direction was applied to characterize the interlayer bond strength. With a decrease of the viscosity of PEEK, an increase of interlayer bond strength ensued. It is expected that these findings could provide more insight for 3D printing of PEEK. (c) 2020 Society of Chemical Industry

Automated summary

This study investigated the mechanical properties and microstructure of PEEK printed with different nozzle temperatures and various molecular weights. It was found that PEEK-033G with medium molecular weight exhibited good fluidity and when printed at a nozzle temperature of 410 degrees C using a high-temperature chamber 3D printing system, the defects were significantly reduced, resulting in tensile strength and flexural strength close to the performance obtained from injection molding. Additionally, a decrease in the viscosity of PEEK led to an increase in interlayer bond strength.