Thermal and oxidation protection of carbon fiber by continuous liquid phase pre-ceramic coatings for high temperature application

Abstract

Thermal and oxidation resistant coating is necessary for carbon fiber (CF) in CF reinforced concrete (CFRC) composite application in order to fulfil a high level of safety standard in case of fire. Pre-ceramic coatings such as Polysilazane, Polysiloxane, and Methyl silicone resin have been deposited on CF filament yarn by means of wet chemical continuous dip coating method. The surface analyses e.g. scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and infrared spectroscopy (IR) results showed the changes of surface morphology by the coatings. Thermo gravimetric analysis (TGA) revealed that the high temperature (up to 800 °C) oxidation stability of CF was significantly improved with coatings. Thermo-mechanical properties also significantly enhanced up to 600 °C. CF yarn retains its original strength and elasticity modulus/stiffness at 700 °C due to thermal and oxidation resistant coatings.