Structure and thermo-mechanical properties of CTBN-grafted-GO modified epoxy/DDS composites

Abstract

Carboxyl terminated poly(acrylonitrile-co-butadiene) (CTBN) is grafted on to graphite oxide (GO) to prepare GCTBN in order to improve the dispersion and interfacial bonding between GO and epoxy resin in an epoxy/DDS system. GCTBN was characterized by FTIR, XPS, Raman spectroscopy, XRD, TEM, TOM (morphology) and TGA. All these studies reveal the grafting of CTBN with GO. The thermal stability of GCTBN was found to improve considerably. The TEM micrograph of epoxy/GCTBN reveals an excellent dispersion of GCTBN in the epoxy matrix. Tensile strength (ca. 25%), tensile modulus (ca. 34%), tensile elongation (ca. 10%), and fracture toughness (ca. 128%) improved remarkably for GCTBN modified epoxy matrix. SEM micrographs reveal no sheet pull out for GCTBN modified epoxy, due to the complete wetting of GCTBN by the epoxy matrix. This confirms effective sheet/matrix interfacial bonding for the GCTBN modified epoxy matrix. Moreover, the viscoelastic properties reveal a very high modulus and improved T_g for the epoxy/GCTBN when compared with the neat crosslinked epoxy.