Fabrication and characterisation of functional gradient hydroxyapatite reinforced poly (ether ether ketone) biocomposites

Biomaterials usually require simultaneous possession of excellent performances such as bioactivity, mechanical and bio-tribological properties to meet biomedical application requirements. In this reported work, the bioactive and mechanical properties of biocomposites were simultaneously optimised according to the functional gradient design idea. The functional gradient nano-hydroxyapatite reinforced polyetheretherketone (nano-HA/PEEK) biocomposites were fabricated through the layer-by-layer casting method and incorporation with thermal pressure moulding technology. The microstructure and morphology were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared (FTIR). The result of the XRD study verified that the crystallinity of the PEEK matrix obviously improved after heat treatment. The SEM observation revealed that the size of HA particles in the biocomposites was in the nanometre scale. Furthermore, two typical morphologies such as encapsulated- and dimple-like microstructures were observed by SEM. The FTIR study showed that the interaction between nano-HA particles and the PEEK molecule existed. Both the SEM and FTIR studies results revealed that the morphology and microstructure in the functional gradient HA/PEEK biocomposites were beneficial for the improvement of the mechanical properties of the gradient biocomposites.