A Comprehensive Evaluation of Mechanical, Thermal, and Antibacterial Properties of PLA/ZnO Nanoflower Biocomposite Filaments for 3D Printing Application

Functionalities of 3D printing filaments have gained much attention owing to their properties for various applications in the last few years. Innovative biocomposite 3D printing filaments based on polylactic acid (PLA) composited with ZnO nanoflowers at varying contents were successfully fabricated via a single-screw extrusion technique. The effects of the varying ZnO nanoflower contents on their chemical, thermal, mechanical, and antibacterial properties were investigated using Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and tensile testing, as well as qualitative and quantitative antibacterial tests, respectively. It was found that the ZnO nanoflowers did not express any chemical reactions with the PLA chains. The degrees of the crystallinity of the PLA/ZnO biocomposite filaments increased when compared with those of the neat PLA, and their properties slightly decreased when increasing the ZnO nanoflower contents. Additionally, the tensile strength of the PLA/ZnO biocomposite filaments gradually decreased when increasing the ZnO nanoflower contents. The antibacterial activity especially increased when increasing the ZnO nanoflower contents. Additionally, these 3D printing filaments performed better against Gram-positive (S. aureus) than Gram-negative (E. coli). This is probably due to the difference in the cell walls of the bacterial strains. The results indicated that these 3D printing filaments could be utilized for 3D printing and applied to medical fields.

Automated summary

This study successfully fabricated innovative biocomposite 3D printing filaments based on polylactic acid (PLA) and zinc oxide (ZnO) nanoflowers. The effects of different ZnO nanoflower contents on the chemical, thermal, mechanical, and antibacterial properties of the filaments were investigated. The results showed that the ZnO nanoflowers did not react with the PLA chains, and the crystallinity of the filaments increased while the tensile strength decreased with increasing ZnO nanoflower contents. Additionally, the antibacterial activity of the filaments increased with increasing ZnO nanoflower contents, and they showed better performance against Gram-positive bacteria than Gram-negative bacteria.