Properties of poly (lactic Acid)/ hydroxyapatite biocomposites for 3D printing feedstock material

Abstract

In this study, biocomposites as feedstock material for 3D printing were produced by poly (lactic acid) (PLA) as a polymer matrix and Hydroxyapatite (HAP) as reinforcing filler for potential use in biomedical applications. Biocomposites filament from PLA and different HAP content varying from 1–10 wt% were prepared from extrusion and then injection moulding process. The impact of HAP loading on the properties of biocomposites was investigated for crystallinity, density, hardness, tensile, impact, flexural, melt flow index (MFI), thermal properties and biomineralization studies. The formation of PLA/HAP biocomposites was confirmed by fourier transform infrared spectroscopy (FTIR). The hydrophilicity of the biocomposites was studied by contact angle analysis. Dispersion of HAP into PLA matrix was confirmed by scanning electron microscopy (SEM) and optical microscopy. The HAP addition increased the density of the composites. From mechanical analysis PLA/HAP composites containing 1–5 wt% showed an increase in tensile modulus. The Shore D hardness of the composites increased with increase in wt% of HAP content. The maximum hardness was achieved for 10 wt% of HAP content i.e., 87 ± 0.1, which is about 6.1% more than neat PLA. The MFI increased with rise in HAP content that gives a positive opinion of reinforcing PLA composites without deteriorating the processability. The hydrophilicity of the biocomposites was slightly increased after the addition of HAP. From thermal analysis it was concluded that the thermal stability of the biocomposites increased when compared with neat PLA. From the Biomineralization studies formation of apatite layer on PLA composites was confirmed by SEM analysis.