The effect of hydroxyapatite particle shape, and concentration on the engineering performance and printability of polycaprolactone-hydroxyapatite composites in bioplotting

In this study, medical poly [ε-caprolactone] (PCL) was used as the matrix material for the development of composites, with hydroxyapatite (HAp) particles with angular and spherical shapes employed as additives. Pellets of such composites were created with five different filler concentrations in the range of 0.0 up to 8.0 wt% (2.0 wt % increase). Three-dimensional (3D) specimens suitable for investigation were bioplotted using the corresponding pellets. The mechanical behavior of the samples was studied in terms of their tensile and flexural characteristics. Rheological and thermal investigations were conducted, and the morphology and chemical structure were investigated using field-emission scanning electron emission SEM and EDS spectroscopy, respectively. A μ-CT scanning course was employed to evaluate the inbound porosity and dimensional conformity of the specimens. The greatest enhancement in the engineering response of the specimens was observed at a tensile strength of 6.0 wt % PCL/angular HAp, showing a 17.0 % increase over pure PCL. The results demonstrate the potential of HAp as a reinforcing agent for polymers in medical applications using bioplotting. The key findings suggest that the shape and concentration document a significant impact on their mechanical performance.