Processing‐structure‐property relationship of multilayer graphene sheet thermosetting nanocomposites manufactured by calendering

Abstract

The dispersion state of multilayer graphene sheets in polymers has a strong impact on the properties of the nanocomposite, and is driven by the processing parameters of the dispersion method. Herein, multilayer graphene sheet/vinyl ester nanocomposites were manufactured using a three‐roll mill. The roller gaps and number of processing cycles were varied to study their effect on the dispersion state and their relationship with the effective electromechanical properties of the nanocomposites. It was found that reducing the roller gaps and increasing the number of processing cycles yields smaller (up to 7.4 μm in diameter) and more densely packed (up to ~1500 agglomerates/mm2) agglomerates. Nanocomposites manufactured with the three‐roll mill contain agglomerates up to 75% smaller and more densely packed than those manufactured with an ultrasonic tip. Electrical conductivity was higher for moderately‐sized, homogeneously distributed agglomerates (23 μm in diameter) with a high areal density (~920 agglomerates/mm2), while smaller agglomerates reduced electrical conductivity. Smaller agglomerates increased the mechanical properties but decreased the piezoresistive sensitivity. The agglomerate density proved to be a key factor governing the piezoresistive sensitivity, with a lower number of agglomerates per unit area promoting higher gauge factors.

Novel olive stone biochar particle network for piezoresistive strain sensing in natural fiber‐reinforced composites

“…This should work in favor of the smaller particle size. [61][62][63][64][65] The opposite trend is found. This may be partly due to the different intrinsic conductivities of the particles.…”

On the large amplitude vibration of shallow sandwich shells with FG-GNPRP core considering initial geometric imperfections

“…On substituting expressions for stress, i.e. σ and then for total strain from equations (18), and (11) in equation ( 21)…”

“…[13][14][15] The graphene nanoplatelets provide better capability than CNTs in terms of load transfer because of larger specific surface area that results in strong bonding of GNP with matrix material as reported by Rafiee et al 16 Additionally, GNP can be produced with low cost relatively, hence it has attracted many researchers to develop GNP reinforced FG-porous materials. [17][18][19] In past few years, many researchers reported their work on the analysis of GNP reinforced FG-porous structures. Dong et al 20 performed free vibration of FG-GNPRP cylindrical shell in which they employed first-order shear deformation theory (FSDT) to develop fundamental equations while including shells with spinning motion.…”

Thermoresistivity of Carbon Nanostructures and their Polymeric Nanocomposites

“…For GS/polymer composites, the morphology (lateral size, number of layers) and physicochemical properties (surface area, functional groups) of the graphenic sheets is of paramount importance for the formation of the electroconductive network, see, e.g., ref. [125]. However, the physicochemical properties of the GSs are rarely provided in publications reporting the thermoresistive response of polymer composites, so reliable structure‐property relationships which drive fundamental conclusions are hard to construct.…”