Preparation of a novel epoxy/SiO2 hybrid coating

In this paper, epoxy/SiO2 hybrid coating was successfully prepared through sol-gel technique, the structure and thermal properties of epoxy/SiO2 hybrid coating were investigated. First, gamma-isocyanatopropyltriethoxysilane 11 (KBE-9007) 11 was used to modify the epoxy resin so that the ethoxysilane could be grafted on the epoxy resin. Nano-SiO2, precursor was synthesized by tetraethoxysilane(TEOS) through sol-gel technique. Then the modified epoxy resin and the nano-SiO2 precursor were mixed for 4 hours to let the macromolecules of epoxy resin graft on the surface of nano-SiO2 and modified nano-SiO2 precursor was obtained. At last, epoxy/SiO2 hybrid coating was produced by using the modified nano-SiO2 precursor. The graft reaction was confirmed by the analyses of FT-IR. The analyses of XPS indicated that there are lots of SiO2 particles and Si-C covalent bonds on the surface of epoxy/SiO2 hybrid coating, they also suggested that most TEOS had changed into SiO2 particles and Si-C covalent bond had been formed between epoxy resin and SiO2. The analyses of SEM fracture surface image of epoxy/SiO2 hybrid coating showed that SiO2 particles dispersed in epoxy matrix homogeneously and the size of the particles was between 50nm and 100 nm. Thermoanalysis Instrument was employed to detect the thermal properties of epoxy coating and epoxy/SiO2 hybrid coating, the results indicated that the thermal decomposition temperature of epoxy/SiO2 hybrid coating is 21.7 degrees C higher than that of epoxy coating, the thermal properties of the epoxy/SiO2 hybrid coating were improved because of the introduction of nano-SiO2.