Hyperbranched polysiloxane functionalization of graphene oxide for improved mechanical properties of cyanate ester nanocomposites

Abstract

We report an efficient and novel method to functionalize graphene oxide nanosheets with hyperbranched polysiloxane and successfully compound them with dicyclopentadiene bisphenol dicyanate ester resin to prepare nanocomposites. Fourier transform infrared spectra were used to examine the surface functionalization of graphene oxide. The effects of functionalized graphene oxide on the mechanical, thermal, dielectric and water-resistant properties of dicyclopentadiene bisphenol dicyanate ester resin were investigated systematically. Results of differential scanning calorimetry (DSC) show that the addition of modified graphene oxide can facilitate the curing reaction of dicyclopentadiene bisphenol dicyanate ester. Compared with pure dicyclopentadiene bisphenol dicyanate ester resin, the impact and flexural strengths of the nanocomposite materials are improved markedly with up to 60% and 47% increasing magnitude, respectively. Meanwhile, the modified graphene oxide/dicyclopentadiene bisphenol dicyanate ester systems show lower and more stable dielectric constant and loss than pure dicyclopentadiene bisphenol dicyanate ester resin over the testing frequency from 10 to 60 MHz. In addition, the thermal stability and moisture resistance of modified graphene oxide/dicyclopentadiene bisphenol dicyanate ester nanocomposties are also superior to that of pure dicyclopentadiene bisphenol dicyanate ester resin.