Advanced mechanical and thermal characterization of 3D bioextruded poly(e-caprolactone)-based composites

Purpose The purpose of this paper is to study the effect of nano hydroxyapatite (HA) and graphene oxide (GO) particles on thermal and mechanical performances of 3D printed poly(ε-caprolactone) (PCL) filaments used in bone tissue engineering (BTE). Design/methodology/approach Raw materials were prepared by melt blending, followed by 3D printing via 3D Discovery (regenHU Ltd., CH) with all fabricating parameters kept constant. Filaments, including pure PCL, PCL/HA and PCL/GO, were tested under the same conditions. Several techniques were used to mechanically, thermally and microstructurally evaluate properties of these filaments, including differential scanning calorimetry, tensile test, nano indentation and scanning electron microscope. Findings Results show that both HA and GO nano particles are capable of improving mechanical performance of PCL. Enhanced mechanical properties of PCL/HA result from reinforcing effect of HA, while a different mechanism is observed in PCL/GO, where degree of crystallinity plays an important role. In addition, GO is more efficient at enhancing mechanical performance of PCL compared with HA. Originality/value For the first time, a systematic study about effects of nano HA and GO particles on bioactive scaffolds produced by additive manufacturing for BTE applications is conducted in this work. Mechanical and thermal behaviors of each sample, pure PCL, PCL/HA and PCL/GO, are reported, correlated and compared with literature.