Characterization, dielectric properties, and mechanical properties of cyanate epoxy composites modified by KH550-AlOOH@GO

Graphene oxide (GO) was obtained by improved Hummers method; the pseudoboehmite (AlOOH) nanoparticles were prepared with aluminum isopropoxide by Sol–Gel method and modified by the silane coupling agent (KH-550) to get KH550-AlOOH. GO was coated by KH550-AlOOH to gain KH550-AlOOH@GO component. In the meantime, the matrix (E51-BCE) was synthesized from epoxy resin (E51) and bisphenol A cyanate (BCE). KH550-AlOOH@GO/E51-BCE composites were prepared via in situ polymerization, E51-BCE as the matrix and KH550-AlOOH@GO as the reinforcement. The micro-morphology of KH550-AlOOH@GO was investigated by Fourier transform infrared spectrometer (FT-IR) and transmission electron microscope (TEM), and the results showed that KH550-AlOOH was well distributed on the GO sheet and with abundant hydroxyl groups on its surface. The X-ray diffraction (XRD) and scanning electron microscope (SEM) of KH550-AlOOH@GO/E51-BCE composites indicated that KH550-AlOOH@GO was uniformly dispersed in E51-BCE matrix and there was a good interaction between them, which was conducive to the performances of the composite material. Mechanical and dielectric properties of composite also were tested and analyzed. The highest bending strength, bending modulus, and impact strength of KH550-AlOOH@GO/E51-BCE composites were 158.23 MPa, 2.37 GPa, and 46.96 kJ/m², respectively, when the content of KH550-AlOOH@GO was 0.6 wt%, which were 15.72%, 22.42%, and 198.22% higher than those of the matrix resin, respectively. The dielectric constant and dielectric loss of the composite were 3.12 and 0.0027 at 100 Hz.