Preparation and characterization of poly(lactic acid)/boehmite alumina composites for additive manufacturing

The purpose of this work is to investigate the suitability of boehmite alumina (BA) reinforced poly(lactic acid) (PLA) for additive manufacturing with the fused filament fabrication method. PLA filaments with 0-10 wt.% BA content were produced via melt compounding using a twin-screw extruder. Dumbbell-shaped and prismatic specimens were manufactured then by feeding the prepared filaments into a desktop 3D printer. Mechanical, morphological and melt flow properties of the developed samples were determined. The addition of BA decreased the melt flow rate of PLA, however not so much that it would have hindered its suitability for 3D printing. With increasing BA content both the strength and the stiffness of the samples increased slightly at constant deformability and toughness. Scanning electron microscopic images revealed a homogenous dispersion of BA particles within the PLA matrix, although remaining agglomerates were also observed.