Study of the interlayer adhesion and warping during material extrusion-based additive manufacturing of a carbon nanotube/biobased thermoplastic polyurethane nanocomposite

A thermoplastic bio-polyurethane from renewable sources (TPU) and the nanocomposite developed by mixing it with carbon nanotubes (CNT) are investigated as potentially adequate for Material Extrusion-based Additive Manufacturing (EAM). Thermal rheological features studied perspective of their liaisons printing adequacy conditions. As predicted rheology, both samples show good performance in filament elaboration flow nozzle. Warpage is observed TPU, but not nanocomposite, which due to effect CNT nanoparticles on polymer chains dynamics. At velocities, interlayer adhesion strength independent velocity implying that there no significant chain orientation can induce changes TPU entanglements. The shows a lower welding strength, notwithstanding have same entanglements density. This explained considering higher viscosity TPU/CNT, compared reduces melt diffusion coefficient.