Binary Resin-Curing Agent Systems for Fabricating Epoxy and Graphene Oxide-loaded Epoxy Films

Abstract

In this research, diglycidyl ethers of bisphenol-A (BADGE) and polyethylene glycol (PEGDGE) were binarily cured with a mixture of diamine curing agents including isophorone diamine and polyethylene glycol diamine (PEGDA) in the absence/presence of aminated graphene oxide nanoplatelets (AGNPs, 0.5 wt.%). Four molar ratios of diglycidyl ethers and curing agents were used stoichiometrically in isothermal curing systems. The films prepared from the epoxy networks were entirely strong and pliable. All epoxy thermosets were evaluated using field emission-scanning electron microscopy (FE-SEM), Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), and diffuse reflectance-ultraviolet/visible spectroscopy (DR-UV/vis). The absorption coefficients of the epoxy and AGNPs-loaded epoxy materials decreased with increasing the molar ratio of PEGDGE resin and polyethylene glycol diamine curing agent. According to dynamic mechanical analysis no phase heterogeneity occurred in the structure of the prepared thermostats. When the thermoset materials were loaded by AGNPs filler, the peaks associated with alpha relaxations shifted to higher temperatures. Moreover, thermogravimetric analysis demonstrated that the thermal stability of the prepared epoxy thermosets slightly increased after the addition of the nanoplatelets. In addition, the thermal resistance of the prepared thermosets decreased to some extent by increasing the participation rate of monomers containing polyoxyethylene.