Epoxy/p‐phenylenediamine functionalized graphene oxide composites and evaluation of their fracture toughness and tensile properties

Abstract

ABSTRACT:In an attempt to enhance the mechanical properties of epoxy/graphene-based composites, the interface was engineered through the functionalization of graphene oxide (GO) sheets with p-phenylenediamine; this resulted in p-phenylenediamine functionalized graphene oxide (GO-pPDA). The morphology and chemical structure of the GO-pPDA sheets were studied by spectroscopic methods, thermal analysis, X-ray diffraction, and transmission electron microscopy. The characterization results show the successful covalent functionalization of GO sheets through the formation of amide bonds. In addition, p-phenylenediamine were polymerized on graphene sheets to form crystalline nanospheres; this resulted in a GO/poly(p-phenylenediamine) hybrid. The mechanical properties of the epoxy/ GO-pPDA composite were assessed. Although the Young's modulus showed improvement, more significant improvements were observed in the strength, fracture strain, and plane-strain fracture toughness. These improvements were attributed to the unique microstructure and strong interface between GO-pPDA and the epoxy matrix.

New polyurea MWCNTs nanocomposite films with enhanced mechanical properties

“…Comparing our values with literature data, one can observe that in our case both the tensile strength and Young modulus values are improved. This modification can be attributed to the elongated fibrous MWCNTs structure that allows sliding of one tube over another resulting in an improved strain resistance.…”

Reinforcing effect of amine‐functionalized and carboxylated porous graphene on toughness, thermal stability, and electrical conductivity of epoxy‐based nanocomposites

“…On the contrary, the coarse and wrinkled surfaces of the nanocomposites reinforced with 2.0 wt % of CNPG and ANPG, as respectively, shown in Figure (c,d), ascertain effectual changes from a brittle state to a ductile behavior through presenting much more irregular and nonuniform fracture lines. Finally, the results of the morphological examinations are in total agreement with the outcomes of the mechanical analysis …”

“…Incorporation of nanomaterials into polymer composites has drawn tremendous attention as an efficient and cost‐effective method for improving properties in the past few decades . In addition, as there is a growing demand in industry for polymeric nanocomposites, particularly epoxy‐based ones, due to their potential applications, reinforcing their properties has become an essential issue .…”

Chitosan–graphene oxide nanocomposites: Effect of graphene oxide nanosheets and glycerol plasticizer on thermal and mechanical properties

“…Different strategies have been reported for dispersing GO into polymer matrices to enhance their multifunctional properties. One of the most commonly used processing routes consists of dispersing GO or modified GO by covalent bonding with other molecules into polymer matrix through relatively weak dispersive forces . Another developed method is the introduction of covalent linkages between GO and the supporting polymer to promote stronger interfacial bonding …”