The Research On Surface Modification Of Graphene Oxide As Well As Its Composite With Epoxy Resin

Graphene has recently been used in the future Hi-Tech field owing to its outstanding mechanical properties and thermal conductivity own to its unique structure. But the characteristic of its chemical inertia and agglomerates would limite its application.The functionalization to graphene has become an effective way to dissolve this problem. In this paper, graphite oxide was prepared by improved Hummers mothed, then the GO was obtain after ultrasonic treatment. GO sheets suspended in water with Na OH first to end-capping before GO was functionalized by grafting low-cost bisphenol A(BPA). On the basis of this, functionalized GO was used to modify epoxy resin(EP) and then the mechanical, thermal properties of modified composites were investigated.Firstly, the two kinds of GO which were made by traditional Hummers and improved Hummers method respectively were characterized by Fourier transform infrared(FTIR) spectroscopy, thermogravimetric analysis(TGA), X-ray diffraction(XRD). The results show that significant epoxy groups were on the surface of IGO. The greater interlayer spacing of IGO make it more beneficial to obtain a lower number of layers of graphene oxide with more intact crystal structure.Secondly, On the basis above, we explore reaction conditions between IGO and BPA. In order to prevent phenolic hydroxyl and carboxyl on the surface of IGO impacts follow-up work, we first adopt the Na OH solution treatment on the sealing end, sealing end IGO(SIGO), and Then completing the surface modification of IGO. The results of FT-IR, XPS and SEM show that bisphenol A have been introduced on to the surface of IGO. XRD results show that crystal structure of IGO has changed after modified. The dispersion stability of GO suspension analysis indicate that functionalized GO have the highest dispersion stability under the same circumstances compared to unfunctionalized GO.Finally, IGO/EP、SIGO/EP and IGO-BPA/EP composites were made by solution blending method and then the effects of before and after functionalization GO, different amounts of GO on the mechanical, thermal properties of the composites were surveyed. Furthermore, the dispersion of modified GO and unmodified GO in EP was investigated. The results show the modified GO help to improve the mechanical properties with the adding of 0.5wt% and heat stability of the composites compared to GO.