Poplar as Biofiber Reinforcement in Composites for Large-Scale 3D Printing.

The economic viability of the biofuel industry could be improved by adding a high-value revenue stream for biomass supply chains: bioderived composites for the rapidly expanding large-scale additive manufacturing industry (i.e., 3D printing). Using fibrillated fibers derived from biomass (e.g., Populus) to reinforce polymers for 3D printing applications would be less expensive compared to using conventional carbon fibers. Poplar fibers of different mesh sizes (<180, 180-425, 425-850, and 850-2360 μm) were used to prepare poplar-polylactic acid (PLA) composites. The poplar/PLA composites were successfully printed using a large-scale 3D printer to create a podium support. The tensile strength of the composites increased from 34 to 54 MPa as the poplar fiber size decreased. The fracture surfaces of composites derived from smaller poplar fibers (<180 μm) were more compact with fewer voids compared with the composites made with larger poplar fibers. Because of the porous and hollow microstructures, smaller poplar fibers contained more pores on their outer surfaces, which were available for the access and penetration of PLA. Poplar has potential for use as a thermoplastic reinforcement for large-scale 3D printing.