Mechanical and Biological Characterization of Pressureless Sintered Hydroxapatite-Polyetheretherketone Biocomposite

Abstract

Bioactive particulate reinforced polymer composite comprising synthetic Hydroxyapatite (HA) and Polyetheretherketone (PEEK) has been fabricated by injection molding for loadbearing applications in these past few years. The limited degree of customization of injection molding process and the high cost of the mold fabrication and processing cost lead to the fabrication of HA-PEEK composites by pressureless sintering method. The aim of the project is prepared a HA-PEEK composite block from HA-PEEK powder blends using simple detachable cubic stainless steel mold in the furnace with specific temperature and duration. The resultant HA-PEEK composite block will be machine with CAD machining system to produce desired final shape and size of the implant device. The microstructural observations by scanning electron microscopy (SEM), mechanical testing and biological testing of the composites were performed. The averaged tensile and compressive strengths were around 15 MPa and 55 MPa respectively. On the other hand, biological tests showed very positive results which verified bioactivity, biocompatibility and nontoxicity of the composite with the formation of biological apatite layer deposited on the surface of the materials which is critical to establishing bonding between living tissue and biomaterials, without forming the fibrous tissue among them. These results suggested that pressureless sintered HA-PEEK biocomposites have the potential to replace injection molded composites in the loadbearing applications.