1Faculty of Polymer Engineering, Sahand University 2Faculty of Polymer Engineering, Sahand University 3Faculty of Polymer Engineering, Sahand University 4Faculty of Polymer Engineering, Sahand University 5Faculty of Polymer Engineering, Sahand University
Chemical incorporation of epoxy-modifed graphitic layers in epoxy/novolac phenolic resin matrices was carried out through co-curing of epoxy and novolac resins using triphenylphosphine as catalyst. First, (3-glycidyloxypropyl) trimethoxysilane (GPTMS) was grafted on graphene oxide (GO) surface to obtain epoxidized GO layers. Then epoxy resin and GPTMS-mod�ifed GO were incorporated into thermosetting reaction using novolac resin in the presence of triphenylphosphine. Covalent attachment of GPTMS-modifed GO to the resin matrices resulted in a hybrid composite with high thermal characteristics.
Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, thermogravimetric analysis (TGA), X-ray dif�fraction, and Raman spectroscopy were used for approving modifcation of GO with GPTMS. The images resulted from scanning and transmission electron microscopies exhibited GO layers with lots of creases turning to smooth layers with a few thin ripples after modifcation with GPTMS. TGA results showed that thermal characteristics of resins were improved by the addition of GPTMS-modifed GO. Char residue of the hybrid composites containing 0.5 and 1 wt% of GPTMS-modifed GO reached 28.1 and 34.3%, respectively. Also, their maximum thermal degradation temperature was also increased by the incorporation of GPTMS-modifed GO.