Preparation and mechanical properties of bone mimicking hydroxyapatite/liquid crystal polymer composite

Hydroxyapatite/thermotropic liquid crystal polymer (HA/Vectra A950) composites were processed with optimized parameters. When the HA/Vectra A950 mass ratio is less than 10/100, the composite exhibits a core-shell structure. The HA particles are mainly dispersed in the core part, while the skin layer is composed of highly oriented Vectra A950 microfibrils. The tensile modulus and strength of the composite are comparable or even higher than those of natural bone. With the increase of HA content, the core-shell structure disappears gradually, but the defects increase. With the increase of HA/Vectra A950 mass ratio to 20/100, the composite mechanical properties, fracture strain in particular, significantly decrease. This is attributed to the interface adhesion between HA particles and Vectra A950 matrix is poor. To ensure the bioactivity, HA content of the bone mimicking composite needs to be close to that of natural bone. Therefore, the interface of HA/Vectra A950 needs to be modified to improve their adhesion.