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The use of graphene sheets as a reinforcing agent in polymeric nanocomposites is increasing owing to their exceptional mechanical and thermal properties. Herein, graphene oxide (GO) is used as the reinforcing material in natural rubber (NR)/GO elastomeric nanocomposites to enhance the mechanical and thermomechanical properties of the composites. NR/GO composites of different compositions were prepared through consecutive melt-mixing and two-roll mixing processes. Mechanical, thermomechanical, and thermal stability studies of the prepared composites were carried out in accordance with ASTM standards. The incorporation of only 5 wt.% GO in the NR elastomer led to a 72–76% improvement in the tensile strength of the NR/GO composites. Simultaneously, the viscoelastic properties, namely storage modulus ( E ′ ), loss modulus ( E ′ ′ ), and glass transition temperature ( T g ) of the composites improved, and thermal decomposition of the composites decreased because of excellent interaction between the polymeric networks of the elastomers and the GO sheets. [ABSTRACT FROM AUTHOR]

ABSTRACT: 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, KIC) achieved from single edge notched bending testing is improved by ∼111% against pure epoxy at 0.1 wt % loading of TZ functionalized GO. Further, the tensile strength and Young's modulus are improved by ∼30.5% and 35%, respectively. Thermal stability of the composites as investigated by thermogravimetric analysis showed 29 °C rise in onset degradation temperature for 0.1 wt % TZ functionalized GO incorporated composite. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46124. [ABSTRACT FROM AUTHOR]

Thermally reduced graphene oxide (TRGO) was incorporated as a reinforcing filler in the epoxy resin to investigate the effect on the mechanical properties of carbon fiber (CF)/epoxy composites. At first, the epoxy matrix was modified by adding different wt % of TRGO from 0.05 to 0.4 wt%followed by the preparation of TRGO/CF/epoxy composites througha vacuum-assisted resin transfer molding process. The prepared TRGO was characterized by using Fourier transform infrared spectroscopy, Raman Spectroscopy and field emission scanning electron microscopy (FE-SEM) techniques. It was observed that the wrinkled structure of synthesized TRGO may be helpful to interlock with the epoxy resin and CF.The inter-laminar shear strength, in-plane fracture toughness and impact strength increased by ~67%, 62% and 93% at 0.2 wt % of TRGO loading in the CF/epoxy composites as compared to the CF reinforced epoxy. The mechanical properties of the hybrid composites decreased beyond the 0.2 wt % of TRGO incorporation in the epoxy resin. The fracture surfaces of the hybrid composites were studied by FE-SEM image analysis to investigate the synergistic effect of TRGO in the CF/epoxy composite. This study suggested that TRGO could be used asgood nanofiller to resist the matrix and fiber fracture. [ABSTRACT FROM AUTHOR]