Understanding the Role of PBAT Content and Raster Orientation on the Mechanical Performance of Material Extrusion...

Area of Science:

• Materials Science
• Polymer Science
• Additive Manufacturing

Background:

• Poly(lactic acid) (PLA) is a common feedstock for material extrusion (MEX) 3D printing.
• Improving PLA's ductility is crucial for expanding its applications.
• Poly(butylene adipate-co-terephtalate) (PBAT) is a flexible polymer that can enhance PLA properties.

Purpose of the Study:

• To investigate the effects of blending PLA with PBAT on mechanical properties.
• To evaluate the influence of raster angle (RA) on the mechanical performance of PLA/PBAT blends.
• To determine the optimal blend composition and RA for improved 3D-printed part performance.

Main Methods:

• PLA was blended with 0-40 wt.% PBAT and processed into filaments for MEX 3D printing.
• Specimens were printed at three raster angles (0°, ±45°, 90°) for mechanical testing.
• Tensile strength, modulus, and impact strength were measured, alongside melt flow index (MFI) and SEM analysis.

Main Results:

• Increasing PBAT content reduced MFI and weakened inter-bead bonding.
• Tensile strength and modulus decreased with higher PBAT content and RA.
• Impact strength significantly improved with PBAT addition, with the highest value at 40 wt.% PBAT and ±45° RA.

Conclusions:

• Both PBAT concentration and RA significantly impact the mechanical properties of 3D-printed PLA.
• PBAT addition enhances ductility and impact strength, though it reduces tensile strength and modulus.
• Optimal RA and PBAT content are critical for tailoring mechanical performance in 3D-printed components.