Graphene Oxide Modified Epoxy Resin And Polyurea

Graphene oxide(GO)was synthesized using 325 mesh flake graphite as the raw material,and characterized by FTIR,XPS,and XRD.It was confirmed that GO contained-COOH,-OH,-C-O-C-,the oxygen content was 35.99%,and the GO interplanar spacing was larger than flake graphite.Modified GO(KGO)was synthesized using silane coupling agent KH550,and characterized by FTIR,XPS,XRD,AFM.It was confirmed that KH550 was grafted to GO,and the thickness of KGO layers was about 4nm.KGO was combined with epoxy resin(EP)and polyurea(PUA)to prepare KGO/EP and KGO/PUA composite materials,respectively.The dispersion of KGO in EP and the mechanical properties and thermal stability of KGO/EP were tested.The results showed that KGO can be dispersed in EP stably;the elongation at break and tensile strength of KGO/EP increased first and then decreased as the content of KGO increased.The mechanical parameters reached the maximum value when the content of KGO was 0.5 wt%;SEM result showed that KGO/EP exhibited ductile fracture feature when the KGO content was 0.5 wt%.TG result showed that the addition of KGO can reduced the thermal decomposition rate of EP and increased thermal decomposition temperature in early stage.DSC result showed that the addition of KGO increased the Tg of EP.The mechanical properties,thermal stability,water resistance,oil resistance,and salt resistance of KGO/PUA composites were tested.The results showed that the elongation at break and Tg became significantly higher than pure PUA when the KGO content was 2.5 wt%,but The tensile strength and the Shore A hardness decreased with increasing of KGO,SEM was used to observe the apparent appearance of the fracture surface and the result showed that KGO was evenly dispersed in PUA.TGA result showed that the thermal stability of KGO/PUA was improved compared with pure PUA;the addition of KGO improved the water-,oil-,and salt-water-resistance of KGO/PUA composites.