Synthesis And Characterization Of Polyetheretherketone/Hydroxyaptite Composites Coatings

HA/PEEK biocomposite materials have been recently investigated due to the favorable biocompatibility of hydroxyapatite (HA) and good mechanical properties of polyetheretherketone (PEEK) polymers. However, a large HA content in PEEK composites could deteriorate the mechanical properties of the composite materials, therefore, HA-coated PEEK is a promising implant material to meet the needs of both good mechanical properties and excellent bioactivity. So far HA-coated PEEK has not been studied in depth. In this thesis bioactive HA/PEEK coatings were fabricated successfully by a high temperature sintering process, and the good properties were expected.The HA particles were modifed by the different content (1wt.%, 2wt.%, 3wt.%, and 4wt.%) of silane coupling agent (KH560), and the silane modified HA particles were characterized by fourier transform infrared spectroscopy (FTIR). The results show that 2wt.% KH560 can play the best performance. What's more, the result of X-ray diffraction (XRD) analysis show that KH560 has not influenced the HA crystal structure.The PEEK/HA and PEEK/KH560-HA (HA content is 45wt.%) composite materials were prepared by a solution blending method. These composite were placed on the PEEK substrate (25mm×6mm×3mm), and samples with PEEK/HA and PEEK/KH560-HA composite coatings were prepared after sintering at 270℃for 8min in furnace. XRD results show that the crystallinity of PEEK substrate increased with the increase of the temperature and time of heat treatment. The mechanical properties of different samples were measured, and the results illustrated that the tensile strength of samples with PEEK/HA and PEEK/KH560-HA composite coatings decreased, compared with the samples without coatings, and the samples with PEEK/KH560-HA composite coatings show higher tensile strength and toughness than the samples with PEEK/HA composite coatings, which explained the necessity of the surface modification of HA with KH560. With the increase of the temperature and time of heat treatment, the tensile strength of samples with PEEK/HA and PEEK/KH560-HA composite coatings was enhanced, which was alterated in accordance with crystallinity.The microstructure of the tensile and bending fracture section of the composites was observed using scanning electron microscope (SEM), and the composition of the composite coatings of samples with modified HA by KH560 were investigated by energy dispersive spectrometer (EDS). These results show that the good adhesion between PEEK/HA or PEEK/KH560-HA composite coatings and the PEEK substrate was achieved, therefore, the composite coating materials with both high mechanical properties and good bioactivity can be prepared by this coating process.