Study On The Properties Of Fly Ash/Epoxy Composite Material

The fly ashes/epoxy composite with high contents of fly ashes was prepared by cast molding method, then with glass fiber enhanced. The FTIR was used to investigate the surface modification mechanism of fly ash. Effects of different constituents on mechanical properties, thermal properties, microstructure of the composite material were studied.After surface modification by coupling agent of KH-560, which could lead to an improvement of fly ash/epoxy resin interfacial interaction, the dispersion of fly ash was improved significantly. By IR spectra, we find out that coupling agent componment takes place the chemical bond with the surface structure of the fly ash.The study of mechanical properties showed that, with the increasing of fly ash, the mechanical properties of the composite decrease first and then increase. When the content of FA was500portions, the composite material has better performance. After glass fiber reinforced, the content of GF was20portions, the compressive strength had reached a maximum of129.20MPa, which was enhanced by246%compared with the one of the pure epoxy resin.The study of DMTA showed that, fly ash had negative effects on the glass transition temperature. The change mainly due to the surface hydroxyl groups of fly ash reacted with epoxy resin, what lead to a decreasing of the solidification degree. We found that glass fiber be used to improve crosslinking density and heat stability. When the content of FA was500portions and glass fiber was25portions, the glass transition temperature had reached a maximum of116.45℃, which was increased by8℃compared with the one of the pure epoxy resin.The study of scanning electron microscope showed that the composite appeared cracking phenomenon in low contents of fly ash and appeared particles crushing of fly ash in high contents. It is sayed that the addition of high contents of fly asd made the interfracial bonding of the composite better. After the glass fiber enhanced, the tensile fracture can clearly see that the surface of the glass fiber stained with resin. The glass fiber would hinder the development of micro-cracks which caused by the tensile stress, then made the tensile strength of composite increased.