3D printed human hair-polymer continuous fiber reinforced composites through Vat Photopolymerization process

This study gives insight into the fabrication of 3D-printed human hair polymer composites using the Stereolithography (SLA) technique. Different surface modification techniques have been introduced to overcome the problem of poor interfacial adhesion between the fiber and the matrix. Human hair fibers were modified by grafting with Methacryl Polyhedral Oligomeric Silsesquioxane (MA-POSS) and cold air plasma treatment. The effect of the surface treatment was investigated using single hair pull-out tests, and the results showed that plasma-treated human hair composites showed the best performance in terms of interfacial strength between fibers and matrix. Furthermore, the mechanical properties of 3D-printed human hair composites have been investigated. The results indicate that the ultimate tensile strength has increased by 35% in plasma-treated composites compared to nontreated human hair composites and 100% compared to composites with no reinforcement. Scanning Electron Microscopy (SEM) and an optical microscope were used to study the surface morphology of the modified fibers. Moreover, X-ray Photoelectron Spectroscopy (XPS) was performed to confirm the grafting of MA-POSS on the human hair fibers. In addition, the X-ray Computed Tomography (& mu;-CT) technique has been utilized to analyze voids, fiber volume, and fiber orientation.