Home-made epoxy emulsion sizing agent for treating carbon fibers: Thermal stability and mechanical properties

The thermal degradation kinetics of a home-made epoxy emulsion sizing agent for carbon fiber has been investigated by thermogravimetric analysis (TG). The thermal degradation activation energy, calculated by Flynn-Wall-Ozawa method and Friedman method, is in good agreement with each other, and the values are 214.03 and 220.87kJ/mol, respectively. The reaction order n (4.7414) and frequency factor A (1.6906x10(17)) were determined by Friedman method. The studies by scanning electron microscope, X-ray photoelectron spectroscopy (XPS), tensile strength of single fiber and interlaminar shear strength (ILSS) revealed that the sizing agent had improved the content of oxygen-containing groups on carbon fiber, increased the tensile strength of single fiber, and effectively enhanced the interfacial properties of carbon fiber/epoxy composites.