Polylactide/hemp hurd biocomposites as sustainable 3D printing feedstock

Industrial hemp hurd (HH) is emerging as a bio-based filler in thermoplastic biocomposites. In this paper, HH/polylactide (PLA) biocomposites were developed as fused deposition modelling (FDM) feedstock through parametric analysis of the effects of HH loading with respect to melt flow, rheology, physical, thermo mechanical, and mechanical properties of the biocomposites. Poly (butylene adipate-co-terephthalate) (PBAT) and ethylene-methyl acrylate-glycidyl methacrylate terpolymer (EGMA) were used as toughening and compatibilisation agents respectively in melt-compounding and extrusion to produce FDM filament. The FDM-printed standard samples were compared against corresponding injection-moulded biocomposites. The FDM filament exhibited a diameter tolerance within ±0.02 mm, and roundness variability below 0.03 mm, and the FDM-printed parts with HH loading under 30 phr showed higher impact toughness than the commercial PLA filament control. In addition, the FDM-printed samples exhibited greater dimensional accuracy with increasing HH loading