| Cyanuricchlodide(TCT), hexanediamine(HDM) and 4,4′-Methylenedianiline(DDM) were used to synthesize two kinds of compounds TCTHDM and TCTDDM with four high-activity C-Cl bonds. FT-IR, 1H-NMR FT-IR and 1H-NMR were used to characterize the chemical structures of the novel compounds. Graphene oxide as the precursor, were modified by grafting respectively two kinds of small organic molecule TCTHDM and TCTDDM on the surface. The functional structure and surface morphology of two functionalized graphene oxide TCTHDM-GO and TCTDDM-GO, were confirmed successfully by FT-IR, Raman spectroscopy, X-ray diffraction(XRD) and scanning electron microscope(SEM).By thermo-gravimetric analysis method, we explored the thermal stability of them. In the meanwhile, the layer dispersion of the two kinds of functionalized graphene oxide was also discussed in this paper. The results indicated, compared to graphene oxide, the thermal stability improved and disorder and layer spacing of graphene increased due to insertion of the small organic molecules between layers.The influence of functionalized graphene oxide on curing behavior of epoxy resin composite was studied by Non-isothermal DSC. The result showed that with the increased content of TCTHDM-GO in curing system, exothermal peak temperature and total heat of cure decreased whereas the conversions of cure reaction increased. Kissinger and Ozawa methods were utilized to determine the activation energy(Ea) respectively. Ea decrease when TCTHDM-GO added, which demonstrated that TCTHDM-GO catalyzed the curing behavior of epoxy.Functionalized graphene oxide couldn’t change the two kinds of composite material systems of thermal decomposition process according to TG results. Besides, we studied the change of the energy storage modulus(E’),loss factor(tanδ) and glass transition temperature of epoxy resin composites with the variation of TCTHDM-GO and TCTDDM-GO content by Dynamic Mechanical Analysis(DMA). which demonstrated that adding a certain amount of TCTHDM- GO or TCTDDM- GO could promote epoxy crosslinking, resulting E’ and Tg increasing. Energy storage modulus reached the maximum and increased by 0.475 GPa with 1.4ωt% TCTHDM-GO, besides, the maximum of glass transition temperature was found with 1.0 ωt%. In addition, with 1.4ωt% TCTDDM-GO,glass transition temperature increased by 6.5℃. Finally,the mechanical properties of composites were tested and analyzed. The results showed that a small amount of functionalization graphene oxide could improve the mechanical properties of composites, tensile strength increased by 43%, flexural strength increased by 24%, impact strength increased by 111%. |
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