PLA/MWCNT Nanocomposite: Improved Electrical, Thermal and Antibacterial Properties for Fused Deposition Modelling Additive Manufacturing Applications

Abstract

Incorporation of nanoparticles in Polylactic Acid (PLA) for additive manufacturing is explored to alter the material property to suit its intended application. In this study, PLA is reinforced with multi-walled carbon nanotubes (MWCNT) using two-roll mill for fused deposition modeling (FDM) additive manufacturing. The chemical composition, thermal behavior, electrical, and antibacterial properties of the PLA/MWCNT nanocomposite were investigated. The Fourier transform infrared spectroscopy (FTIR) analysis showed the physical interaction of MWCNT to the PLA matrix. The x-ray diffraction analysis (XRD) data showed that increasing the MWCNT percentage increases the amorphous region and intensity, indicating the nucleating effect of MWCNT on PLA. Differential scanning calorimetry (DSC) analysis showed a decrease in the glass transition and melting temperatures compared to pure PLA by up to 9.36°C and 23.25°C, respectively, while introducing cold crystallization with the addition of MWCNT. The two point-probe resistance measurement showed a decreasing trend in the resistance of the composite which indicates an increase in conductivity as the the amount of MWCNT is increased. The analysis of disk diffusion test concluded that no bacterial growth of Escherichia coli and Staphylococcus aureus happened underneath the sample. Furthermore, the nanocomposite was successfuly extruded into a filament and test samples were 3D printed using FDM. The PLA/MWCNT produced are suitable for the production of a multifunctional filament with improved electrical, thermal and antimicrobial properties for different fused deposition modelling (FDM) additive manufacturing increasing the probable applications and competitiveness of this promising market niche.