Peanut Hull as an Alternative Biocomposite for Polylactic Acid Filament in Fused Filament Fabrication 3D Printing

Biocomposites are of great interest today in the development of fused filament fabrication (FFF) 3D printing filament. The hydrophilic nature of natural fibers limits the reaction between the polymer matrix and the fiber which has driven researchers to search for alternatives. Traditional methods such as injection molding have proven that polylactic acid (PLA) and peanut hull (PH) can be combined. However, producing a good combination of PLA and biocomposites remains a challenge. In this work, the combination of PLA and PH using a twin-extruder to create a FFF 3D printer compatible filament was explored. The highest yield strength of the combination is 70 wt.% PLA and 30 wt.% PH. The average tensile strength and flexural strength produced by PLA/PH is 16.239 MPa and 25.7299 MPa. Using the differential scanning calorimetry and thermogravimetric analysis the composite indicated a reduction in tensile and flexural strength. The mix has a glass transition temperature of 58.92 °C, which is lower than other composites, thus giving faster degradation. These findings demonstrate the feasibility of incorporating PH into PLA, although further optimization is needed to improve the mechanical and thermal stability of the resulting biocomposite filament.