A new method for producing polylactic acid biocomposites for 3D printing with improved tensile and thermo-mechanical performance using grafted nanofibrillated cellulose

In this work, a new methodology was developed to disperse nanofibrillated cellulose (CNF) in polylactic acid (PLA) composites for 3D printing. The nanofibres were modified by grafting PLA onto their surface through in-situ polymerisation of L-lactide. This modification changed subsequent fibre/PLA interaction and enabled the production reinforced microparticles Pickering emulsion approach. We demonstrated that filaments produced with these containing up 20 wt% grafted CNF (g-CNF) can be processed printed using same printing parameters as used neat PLA. samples presented superior tensile properties, enhanced thermo-mechanical stability, dimensionally stable upon crystallisation when g-CNF content is above 10 wt%. When heat-treated after composite achieved an ultimate strength Young’s modulus 72 MPa 5.4 GPa, respectively. Post-printing annealing also increased stability achieving storage at 80 °C 850 times temperature.