Study On Preparation And Properties Of Graphene-based Nanofiller Reinforced Epoxy Composites

Epoxy resins are an important kind of common thermosetting polymer, which exhibits a wide application due to strong adhesion, good electrical insulation, excellent chemical and corrosion resistance, low shrinkage and other characteristic. But the neat epoxy has a low thermal conductivity and electrical conductivity. Also, the crosslinked samples are resistant to brittle impact. Therefore, the researchers often mix the graphene as reinforced filler into epoxy resin system, which is aim to obtain the epoxy based composites with excellent comprehensive performance. This will further expand the application of graphene. In this study, our interest to research the thermal and electrical properties of epoxy composites is focused on the addition of graphene nanoplatelets and SiCNWs-GNPs hybrid nanofillers.First of all, we use Fourier-transform infrared spectra(FTIR), Raman, X-ray photoelectron spectroscopy(XPS) and so on to characterize the pristine graphene nanoplatelets. Meanwhile, the epoxy composites were prepared with the speedmixer, which offer a simple and rapid method to prepare epoxy based composites. Finally, we investigated the effect of GNPs on thermal and electrical properties of epoxy composites. It is found that the graphene nanoplatelets are uniformly dispersed in the epoxy matrix with the blend of speedmixer from the SEM and TEM images of composites. When the GNPs loading is 8wt%, the thermal conductivity of the epoxy composites achieves 1.181 W/m K, which is increased by 627% compared with those of the neat epoxy. In addition, the incorporation of GNPs in epoxy matrix indicated that Vickers hardness got an ideal value at the low weight fractions of GNPs.In addition, we demonstrate the use of reduced iron powders as a catalyst for the growth of SiC nanowires(SiCNWs) on graphene nanoplatelets. At the same time, the synthesized fillers were characterized by SEM, X-ray diffraction, TEM, FT-IR spectroscopy, Raman spectroscopy and thermogravimetric analysis. These analyses confirmed that nanowires had been successfully fabricated on the surface of graphene nanoplatelets. Next, we incorporate the as-prepared SiCNWs–GNPs hybrid nanofllers into an epoxy(EP) matrix to make epoxy composites. Additionally, the thermal and electrical properties of epoxy composites were investigated. To the best of our knowledge, this is the first time to synthesize SiC nanowires on the surface of graphene nanoplatelets with a simple heat-treatment process. The long SiC nanowire, act as a one- dimension intermediary, could contribute to the homogeneous dispersion of the nanofillers in the polymer matrix. It is thought that the bridging effect of the SiC nanowires is the key factor for the improvement of the properties of the composites. In particular, the thermal conductivity of epoxy composite containing 7 wt% SiCNWs–GNPs loading is 65.2% higher than that of neat epoxy, while the electrically conductivity is still in the insulating region.