In situ synthesis of graphene oxide in multi-walled carbon nanotube hybrid-reinforced polyetherimide nanocomposites with improved electrical, mechanical and thermal properties

The assembling of two carbonaceous nanomaterials to fabricate 3D hierarchical graphene-carbon nanotube hybrid is the superlative strategy to synergistically impart electrical and mechanical properties to polymers. In the present study, we have evaluated the effects of nanoscale hybridization of graphene oxide (GO) and multi-wall carbon nanotube (MWCNT) on the electrical, mechanical and thermal properties of polyetherimide (PEI) nanocomposites reinforced by GO-MWCNT hybrid. Synthesis of GO-MWCNT hybrid was confirmed by various spectroscopic measurements. The inclusion of GO-MWCNT hybrid to PEI endows optimum dispersion and better interfacial interactions between GO-MWCNTs and PEI matrix and thus remarkably improved the conductivity, tensile properties and thermal stability of PEI. When the mass ratio of GO to MWCNT is 1:1 and the total filler loading is only 2 wt%, the DC conductivity of the nanocomposite films enhanced by 6 orders of magnitude, the tensile strength increased by fourfold and the Young's modulus increased by sixfold compared to those of pure PEI. The reinforcement efficiency of the GO-MWCNT (1:1) hybrid in terms of the modulus of the nanocomposite was predicted using modified Halpin-Tsai modelling and compared with the experiment results. The present PEI nanocomposite materials could significantly fulfil the demands raised by the aerospace community.