Mechanical Properties of Polylactic Acid/Chitosan Composites by Fused Deposition Modeling

Polymer composites of polylactic acid (PLA) reinforced with chitosan were synthesized through extrusion and additive manufacturing using fused deposition modeling (FDM). The chitosan (Ch) was incorporated into the neat PLA after modification with sodium hydroxide (NaOH). The mechanical properties, including tensile, flexural, and compressive strengths, were assessed using a Universal Testing Machine, alongside impact testing. The results indicated that the tensile stress of the PLA/OCMCh-CA/PEG composite reached a peak of approximately 38 MPa, compared to pure PLA. The PLA matrix exhibited the highest tensile strength at 55.09 MPa, surpassing both PLA + 1% PEG and PLA/OCMCh-CA/PEG composites. Virgin PLA demonstrated a maximum flexural modulus of 3807 MPa, while the values for PLA + 1% PEG and PLA/O-CMCh-CA + 1% PEG were 2390.97 MPa and 2197.08 MPa, respectively. Although the PLA matrix showed lower compressive strength than other composites, the PLA + 1% PEG composite achieved the highest compressive strength at 80.08 MPa. Additionally, impact strength improved from 1.73 KJ/m2 for the PLA matrix to 2.14 KJ/m2 for PLA + 1% PEG. Scanning electron microscopy (SEM) provided detailed images of the fracture surfaces of the composites produced through 3D printing, revealing the structural characteristics of the materials.