Mechanical and thermal performances of epoxy resin/graphitic carbon nitride composites

In this paper, a series of graphitic carbon nitride (g-C3N4) was synthesized under different thermal oxidation etching temperatures and epoxy/g-C3N4 composites were prepared via solution blending. The morphology and structure of g-C3N4 were investigated by transmission electron microscope, X-ray diffraction (XRD), Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. The tensile fracture morphology and structure of epoxy resin (EP) composites were demonstrated by scanning electron microscopy and XRD, respectively. Mechanical properties of EP composites were characterized by tensile testing, and the thermal performances were investigated by dynamic mechanical thermal analysis and thermal gravimetric analysis. The results revealed that the active groups on g-C3N4 sheets increased under thermal oxidation etching and the C to N ratio of g-C3N4 decreased from 0.94 to 0.76 with the increasing etching temperature. Noticeably, the tensile strength of EP composites was enhanced by 58% with the addition of C3N4-NS-500 and the thermal properties were also improved significantly, including T-0.5 (the decomposition temperature at the mass loss of 50%) increased by 21.5 degrees C and glass transition temperature improved by 8 degrees C. (c) 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 137, 48598.