Mechanical properties of a carbon fabric-reinforced epoxy composite with carbon nanotubes and a flame retardant

Abstract

Purpose The purpose of this paper is to present the mechanical and morphological characterization of new multifunctional carbon fibre-reinforced composites (CFRCs) that are able to overcome two of the main drawbacks of aeronautical composite materials: reduced electrical conductivity and poor flame resistance. Multiwall carbon nanotubes and glycidyl POSS (GPOSS) were used to simultaneously enhance electrical conductivity and flame resistance. The effect of these two combined components on the mechanical and morphological properties of the manufactured CFRCs was analysed. Design/methodology/approach This paper describes the mechanical test results obtained for interlaminar shear strength, three-point bending, and tensile and fracture toughness in mode I tests. Carbon fibre-reinforced epoxy resin plates were manufactured in two series with blank resin and CNT+flame retardant GPOSS-enhanced resin. Findings The mechanical properties were decreased by no more than 10 per cent by combined influence of CNTs and GPOSS. Agglomerates of CNTs were observed using scanning electron microscopy. The agglomerates were large enough to be visible to the naked eye as black spots on the delaminated fracture surface. The decrease of the mechanical properties could be caused by these agglomerates or by a changed fibre volume content that was affected by the difficult infusion procedure due to high resin viscosity. Originality/value If we consider the benefit of CNTs as a nanofiller to increase electrical conductivity and the GPOSS as a component to increase the flame resistance of the resin, the decrease of strength seems to be insignificant.

The synergistic effect of CNTs and flame retardants on the mechanical behavior of aerospace epoxy resin

“…Scanning electron microscope (SEM) analysis revealed some areas on the fracture surfaces rich in MWCNTs indicating the need for optimization dispersion techniques. Kadlec et al studied the mechanical behavior of carbon fibre–reinforced epoxy composites enhanced with 0.5 wt% MWCNTs as well as 5 wt% glycidyl POSS (GPOSS). An approximately 10% decrease on the mechanical properties, namely, tensile, three‐point‐bending, interlaminar shear strength as well as G IC fracture toughness properties was found; the authors assumed that the decrease was associated with possible CNTs agglomerations on the fracture surface of the double cantilever beam (DCB) specimens used in G IC fracture toughness tests.…”

Experimental evaluation and modeling of thermal conductivity of tetrafunctional epoxy resin containing different carbon nanostructures

“…A deep analysis concerning the influence of different nanoparticles (CNTs, graphene, nanoclay and nanosilica) on the mechanical characteristics of the epoxy matrix (DGEBA) has been reported in a recent review which highlights the significant potential of CNTs and graphene for improving the mechanical performance of epoxy resins in many engineering applications . In particular, multiwall carbon nanotubes (MWCNTs) can be used to manufacture Carbon Fiber Reinforced Composites (CFRCs) characterized by a relevant decrease in the fatigue crack growth rate of about 80% . In addition to the mechanical performance, there are still many challenges and issues that need to be addressed before the nanofilled resins can be applied for specific structural applications.…”

Fatigue behaviour of innovative multifunctional epoxy resins

“…7 Tensile tests were conducted on single-edge cracked plate specimens of CNT/polycarbonate composites at room temperature and liquid nitrogen temperature (77 K), and the critical loads for fracture instabilities were determined. Kadlec et al 9 studied the mechanical behaviour of carbon fibre-reinforced epoxy composites enhanced with 0.5 wt% MWCNTs as well as 5 wt% GPOSS. In reference, 8 the effect of both CNTs and flame retardants on the mechanical behaviour of an epoxy polymer RTM6-2 subjected to several types of quasi-static loading was investigated.…”

“…The incorporation of the flame retardant GPOSS into the polymer has further deteriorated the mechanical behaviour of the filled material; it was attributed to large CNTs and GPOSS agglomerates identified by scanning electron microscopy (SEM) inspection. Kadlec et al 9 studied the mechanical behaviour of carbon fibre-reinforced epoxy composites enhanced with 0.5 wt% MWCNTs as well as 5 wt% GPOSS. An approximately 10% decrease on the mechanical properties, namely tensile, three-point-bending, interlaminar shear strength as well as G IC fracture toughness properties was found; the authors assumed that the decrease was associated with possible CNT agglomerations on the fracture surface of the double cantilever beam specimens used in G IC fracture toughness tests.…”

“…An approximately 10% decrease on the mechanical properties, namely tensile, three-point-bending, interlaminar shear strength as well as G IC fracture toughness properties was found; the authors assumed that the decrease was associated with possible CNT agglomerations on the fracture surface of the double cantilever beam specimens used in G IC fracture toughness tests. The materials investigated in works 8,9 discussed above, represent good candidates for aircraft structural applications.…”