Layered silicate reinforced polylactic acid filaments for 3D printing of polymer nanocomposites

In this study, the possibility to use a layered silicate reinforced polylactic acid (PLA) in additive manufacturing applications was investigated. In particular, after melt compounding in a twin-screw extruder a filament for 3D printing applications was produced using a single-screw extruder. The influence of nanoclay on mechanical, thermal and viscoelastic properties of the produced filaments was investigated. Differential scanning calorimetry (DSC) results reveal an increase in crystallinity for the nanocomposites and the presence of two crystalline forms (α and α'). Dynamic mechanical thermal analysis (DMA) results show that storage modulus increased for the nanocomposites when compared with neat PLA. Finally, the extruded PLA/clay filaments were successfully 3D printed using fused deposition modelling (FDM) technique. The printed nanocomposites showed a higher elastic modulus (15%) compared to printed samples of neat PLA. Moreover, PLA/clay printed samples present also a better shape stability, showing sharper edges.