The Mechanical Properties Of Polyetheretherketone Biocomposite Reinforced By Nano-Sized Hydroxyapatite

Hydroxyapatite (HA) is widely used in biomedicine as a bioactive material with the ratio of calcium to phosphorus similar to that of the natural bone. Nano-sized HA will possess better bioactivity as compared with micro-sized HA. Polyetheretherketone (PEEK) is a semi-crystalline thermoplastic with excellent mechanical properties, high temperature durability, and good chemical and fatigue resistance. Being one of the most advanced engineering thermoplastics currently available, it has received extensive applications for structural and load-bearing functions in the aerospace and marine industries. For biomedical applications, PEEK offers additional benefits including its ability to be repeatedly sterilized and shaped readily by machining and heat contouring. In recent years, the PEEK polymer has gained much attention in the biomedical field, particularly in the area of load-bearing orthopedic applications. Combining the benefits of HA and PEEK, the PEEK-HA composite will have a good foreground for possible usage as bone analogue materials.Until the present time, most of research has been focused on the mechanical and biological performance of biologically inert PEEK composite such as fiber reinforced PEEK composite. As for bioactive HA reinforced PEEK composite, some work has been conducted on the mechanical properties of PEEK-micro-sized HA composite. However, there has not been any report on the properties of PEEK-nano-sized HA composite. As a consequence, the influence of nano-sized HA on the PEEK is main part of my study.The PEEK matrix composites with 2~15vol.% nano-sized HA were fabricated by injection molding. Vickers hardness and elastic modulus of the composite increased continuously with increasing amount of HA. As for the tensile strength, there was a peak value, occurring at an HA content of about 5vol.%. When the HA content was less than about 5vol.%, the tensile strength increased slightly with increasing HA content, and however it reduced quickly beyond this content almost in a linear fashion. Accordingly, the resulting composite with 5vol.% HA exhibited the optimum improvement of tensile...