Interface engineering for the improvement of mechanical and thermal properties of covalent functionalized graphene/epoxy composites

Functionalized reduced graphene oxide (GO)/epoxy composites are fabricated through solution mixing. GO is functionalized using 3-amino-1,2,4-triazole (TZ) in presence of potassium hydroxide (KOH). KOH is expected to serve dual role as catalyst for nucleophilic addition reaction between GO and TZ, and also as reducing agent. The grafting of TZ moiety on GO is confirmed by Fourier transform infrared spectroscopy, X-ray diffraction, and thermogravimetric analysis. The prepared composites show remarkable improvement in mechanical and thermal stability. The fracture toughness of the composites (critical stress intensity factor, K-IC) achieved from single edge notched bending testing is improved by approximate to 111% against pure epoxy at 0.1 wt % loading of TZ functionalized GO. Further, the tensile strength and Young's modulus are improved by approximate to 30.5% and 35%, respectively. Thermal stability of the composites as investigated by thermogravimetric analysis showed 29 degrees C rise in onset degradation temperature for 0.1 wt % TZ functionalized GO incorporated composite. (c) 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46124.