Polymer grafted graphene oxide: For improved dispersion in epoxy resin and enhancement of mechanical properties of nanocomposite

Investigation of covalently grafted polyacrylate chains onto graphene oxide for epoxy composites with reinforced mechanical performance

“…A strong diffraction peak appears at 2θ = 9.53° in the XRD pattern of GO corresponding to interlayer spacing of 0.93 nm. Compared to the GO, the A‐174 functionalized GO exhibits a broad strong peak at 2θ = 9.05° relating to the interlayer spacing of 0.98 nm which is profited from the existence of A‐174 silane coupling agents among the interlamellar of the GO sheets . Besides, a new weak broad peak appears at 2θ = 18.42° in A‐GO which suggests some aggregations of GO have formed owing to the strong interlayer interaction between the GO sheets.…”

“…30,38 After functionalized by A-174, the intensity of D and G bands significantly decreases and G band shifts from 1585 to 1590 cm −1 revealing the bonded carbon have been converted from sp 2 condition to sp 3 condition which is ascribable to the successful functionalization of A-174 silane. 31,33 Furthermore, the I D /I G ratio of GO decreases from 0.97 to 0.91 after modified by A-174 silane, which is ascribed to the fabrication of covalent bonds between GO and A-174 coupling agents. 30,39 The XRD spectra of GO and A-GO are shown in Figure 5(d).…”

“…In case of the Raman spectra of GO, it is clearly that two strong bands present at 1352 cm −1 (D band) and 1585 cm −1 (G band) which are correlative to the defects and carbon skeleton structure of GO, respectively . After functionalized by A‐174, the intensity of D and G bands significantly decreases and G band shifts from 1585 to 1590 cm −1 revealing the bonded carbon have been converted from sp 2 condition to sp 3 condition which is ascribable to the successful functionalization of A‐174 silane . Furthermore, the I D / I G ratio of GO decreases from 0.97 to 0.91 after modified by A‐174 silane, which is ascribed to the fabrication of covalent bonds between GO and A‐174 coupling agents …”

“…The impact strength of E/PA‐GO‐1 (4.98 ± 0.33 kJ m −2 ) shows no significant difference with that of E/PA‐GO‐3 (5.44 ± 0.49 kJ m −2 ) and increases by 40.3% compared to that of neat epoxy. The improved toughness of these graphene‐based epoxy composites is benefit from (1) the high dispersion of the PA‐GO in the matrix and (2) the strong interfacial compatibility between the PA‐GO sheets and the epoxy resin . However, the impact strength exhibits a decreasing tendency when the addition of PA‐GO is greater than 3 wt %, which may be assigned to the formation of aggregates and microporous in the matrix.…”

“…Various types of polymers are employed to functionalize GO sheets. Sekhavat Pour and Ghaemy fabricated a poly(vinyl imidazole) chains grafted GO (PVI‐g‐GO) using vinyl imidazole and methacrylate functionalized GO nanosheets via radical polymerization method. The results show that the dispersion of PVI‐ g ‐GO has significantly improved in the epoxy matrix.…”