Properties of 3D Printable Poly(lactic acid)/Poly(butylene adipate-co-terephthalate) Blends and Nano Talc Composites

Abstract

Biodegradable poly(lactic acid) (PLA) filaments have been widely used in the fused deposition modeling (FDM) 3D printing technology. However, PLA has low toughness and low thermal resistance that affects printability and restricts its industrial applications. In this study, PLA was compounded with 0 to 40 wt% of poly(butylene adipate-co-terephthalate) (PBAT) and varied content of nano talc at 0 to 40 wt% in a twin screw extruder. The compounds were reextruded to filaments using a capillary rheometer. PLA/PBAT blends and their composite filaments were printed with a FDM 3D printing machine. Morphology, rheological behaviour, thermal characteristic, surface roughness, and mechanical property of 3D printing of the blends and the composites were investigated. Complex viscosity of the blends and the composites increased with increase of the PBAT and the nano talc contents. The incorporation of the nano talc enhanced crystallization temperature and reduced the coefficient of volume expansion of the composites. It was found that the PLA/PBAT blends and composites were excellent in both printability and dimension stability at PBAT content 10-30 wt% and nano talc up to 10 wt%. Interestingly, it was possible to print the composite filaments at an angle up to 75° during the overhang test without a supporter. From the vertical specimens, the surface roughness improved due to the incorporation of the nano talc. Tensile strength of the blends and the composites decreased, whereas elongation at break increased when the PBAT and the nano talc contents were increased. The reduction of tensile strength was attributed to agglomeration of the PBAT dispersed phase and less adhesion between the nano talc and the matrix. It can be noted that the composite 3D printing product showed superior elongation at break up to 410% by adding nano talc 1 wt%. This result suggests that the ductile 3D printable PLA/PBAT blend and the PLA/PBAT-nano talc composite products can be prepared, which shows potential for the commercialized scale.

Improvement of Interlayer Adhesion and Heat Resistance of Biodegradable Ternary Blend Composite 3D Printing

“…As shown in Figure 2 c, the cold crystallization disappeared after the second heating and revealed double melting peaks of the PLA matrix in the blend composites. It was considered that the addition of PBAT, PBS, and nano talc enhanced PLA crystallization and affected the recrystallization and remelting of PLA crystal in the composites [ 22 , 28 ]. Therefore, the incorporation of PBS enhanced the degree of crystallinity of 70/0/30/10 and 70/10/20/10 composite 3D prints, which should improve the heat resistance and mechanical properties of the binary and ternary blend composites.…”

“…Research has shown that blending with ductile polymers, i.e., poly(butylene adipate-co-terephthalate) (PBAT), poly(butylene succinate) (PBS), polycaprolactone (PCL) [ 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 ], and incorporating with particulate fillers and reinforcing fibers [ 25 , 26 , 27 , 28 , 29 ], can improve the limitations of PLA. From our previous study, the binary blend composites from PLA and PBAT blends (PLA/PBAT) and composites with nano talc (PLA/PBAT/nano talc) at 70/30/0/10 exhibited good toughness and printability, and can be presented as alternative filaments in FDM 3D printing [ 28 ]. Nevertheless, interlayer adhesion, anisotropy, and heat resistance should be developed for various applications.…”

Multi-Response Optimization of Tensile Creep Behavior of PLA 3D Printed Parts Using Categorical Response Surface Methodology

“…Lower layer height provides good mechanical strength. As the layer height decreases, the bonding between the layers is strengthened and results in an improved mechanical performance [ 36 , 44 ]. A similar effect is observed for the infill percentage (the quantity of build material), where the mechanical strength improves with an increase in material density [ 45 , 46 ].…”

“…It melts between 180 to 200 °C, depending on other material added to it for color and texture. The important material properties of PLA are given in Table 1 [ 36 , 37 , 38 ].…”

Effect of Layer Directions on Internal Structures and Tensile Properties of 17-4PH Stainless Steel Parts Fabricated by Fused Deposition of Metals

“…The final step (sintering) densifies the part by a thermal treatment that combines the powder particles. Two existing technologies—metal injection molding (MIM) [ 29 , 30 , 31 ] and FDM [ 32 , 33 , 34 ]—have been combined into an FDMet process. MIM is a powder metallurgical process that sinters metal particles at a temperature well below their melting point, thereby conserving heat energy.…”