Investigation of Mechanical Properties of 3D-Printed Poly Lactic Acid with CNT Nano Composites

In recent years, fused deposition modeling has emerged as the most widely used additive manufacturing technique for developing polymeric composite materials. There is limited information available on the flexural, hardness, and impact resistance properties of PLA nanocomposites with carbon nanotube concentrations ranging from 0 to 1wt% in 0.25wt% increments. The nanocomposites were created by combining twin screw extrusion and FDM printing techniques. The microstructure was examined with a scanning electron microscope to assess the printed structure's quality and CNT dispersion in the PLA matrix. The flexural, hardness, and impact tests were carried out in accordance with ASTM D790, D2240, and D256 specifications. The shore D hardness of PLA nanocomposites increased by 18.3% in proportion to the CNT proportion, with the highest value of 84 Shore D obtained in the PLA/1%CNT nanocomposite. Impact strength increased by 144%, while flexural strength increased by 48% with a high percentage of CNT reinforcement. The failure analysis of nanocomposites revealed significant plastic deformation prior to failure, while the impact test showed an increase in impact strength due to the inclusion of CNTs. The failure analysis revealed a two-step failure for nanocomposites and a catastrophic failure for clean PLA, while flexural strength increased with CNT content.