Preparation and In-vitro Degradation Properties of 3D Printed Nano Silica/Hydroxyapatite/Polylactide Biocomposite

Abstract

Nano silica/hydroxyapatite/polylactide biocomposite was 3D printed, the effects of the printing conditions on the mechanical properties of the biocomposite were studied and the in-vitro degradation properties of the biocomposite in the PBS solution were tested. The results show that, the best 3D printing conditions are those with the raster angle of 45°, the printing thickness of 0.2mm and the packed density of 100%.In such situations, the nano silica / hydroxyapatite/polylactide biocomposite containing 2% nano silica has the best comprehensive strengths, at which, the tensile, flexural and impact strengths are 85.62MPa, 126.66MPa and 53.56kJ/m2 respectively. With the prolong of the in-vitro degradation testing time, the tensile and flexural strengths of the biocomposite will decrease, and the impact strength also decrease generally except at the first one or two weeks for the samples containing 0,2% and 4% hydroxyapatite, more water will be absorbed and more weight will be lost. However, the pH value of the PBS solution is almost kept at around 7.35.