Production of carbon fibers modified with ceramic powders for medical applications

Abstract

Carbon fibers and precursor polyacrylonitrile (PAN) fibres that contain either silica or hydroxyapatite particles, imbedded during the spinning process, were studied in this paper. The modified PAN fibers were thermally stabilized using a multi-stage process in the temperature range between 150 to 280 °C in an oxidative environment. Subsequent carbonization leading to obtain carbon fibers was carried on at 1000 °C in an argon atmosphere. The changes of properties of composite precursor fibers taking place during stabilization and carbonization processes were investigated by the combination of Differential Scanning Calorimetry, Fourier Transform Infrared Spectroscopy, Scanning Electron Microscopy equipped with energy dispersive X-ray spectrometer and ultrasonic methods. Mechanical properties, such as tensile strength, static Young’s modulus, elongation at fracture were analyzed at each stage of thermal stabilization process. Additionally some traditional measurements like fiber diameter and mass were studied. Ceramic powders added to the spinning solution were present also in composites fibers after stabilization and carbonization process. Such modification allows to avoid the post-treatment operations, for example by coating or covering with films, which were usually necessary in order to obtain bioactive character of implants. Modification of carbon fibers using calcium phosphate or silica can lead to the development of a new materials for the manufacturing of implants which can establish direct chemical bonds with bone tissue after implantation.