Mechanical Characterization of Graphene—Hexagonal Boron Nitride-Based Kevlar–Carbon Hybrid Fabric Nanocomposites

Abstract

Polymer nanocomposites have been gaining attention in recent years. The addition of a low content of nanomaterials into the matrix improves mechanical, wear, thermal, electrical, and flame-retardant properties. The present work aimed to investigate the effect of graphene and hexagonal boron nitride nanoparticles on Kevlar and hybrid fiber-reinforced composites (FRP). Composites are fabricated with different filler concentrations of 0, 0.1, 0.3, and 0.5 wt.% by using a hand layup process. Characterizations like tensile, flexural, hardness, and impact strength were evaluated separately, heat deflection and viscosity properties of the epoxy composites. The dynamic viscosity findings indicated that a higher concentration of filler material resulted in nano-particle agglomeration. Graphene filler showed superior properties when compared to hexagonal boron nitride filler. Graphene showed optimum mechanical properties at 0.3 wt.%, whereas the hBN filler showed optimum properties at 0.5 wt.%. As compared to Kevlar composites, hybrid (carbon–Kevlar) composites significantly improved properties. As compared to graphene-filled composites, hexagonal boron nitride-filled composites increased scratch resistance. Digimat simulations were performed to validate experimental results, and it was observed that hybrid fabric composites exhibited better results when compared to Kevlar composites. The error percentage of all composites are within 10%, and it was concluded that hybrid–graphene fiber composites exhibited superior properties compared to Kevlar composites.

Bifunctional modification of graphene by phosphorus/nitrogen‐containing silane compounds for smoke suppression and flame retardancy of epoxy resins

“…For graphite, the diffraction peak at 2θ = 26.3 corresponds to the (002) reflection, 36 and it shifts to 17.7 after hydrothermal treatment and modification with flame retardant, indicating that the spacing and dispersibility of graphene increased after hydrothermal treatment. 37 Figure . 1c, d show the 31 P and 1 H NMR spectra of phosphorus/nitrogen-containing silane compound D, respectively. The attribution of these peaks is as follows: 1 H NMR (DMSO-d 6 , 400 MHz): δ = 0.33 ppm (q, 2H, Si CH 2 CH 2 ), 1.1 ppm (q, 2H, CH 3 CH 2 O Si ), 1.22 ppm (q, 2H, CH 3 CH 2 CH 2 -), 2.49 ppm (q, 2H, CH 2 CH 2 NH ), 3.52 ppm (q, 2H, CH 3 CH 2 O Si ), 7-8 ppm (m, Ar H).…”

“…The attribution of these peaks is as follows: 1 H NMR (DMSO-d 6 , 400 MHz): δ = 0.33 ppm (q, 2H, Si CH 2 CH 2 ), 1.1 ppm (q, 2H, CH 3 CH 2 O Si ), 1.22 ppm (q, 2H, CH 3 CH 2 CH 2 -), 2.49 ppm (q, 2H, CH 2 CH 2 NH ), 3.52 ppm (q, 2H, CH 3 CH 2 O Si ), 7-8 ppm (m, Ar H). 31 P NMR (DMSO-d 6 , 400 MHz): δ = 32.7 ppm. The phosphorus in D induces two individual peaks at 32.7 and 14.5 ppm, respectively, while the DOPO peak appears at 13-17 ppm, indicating that the phosphorus/nitrogen-containing silane compound was successfully synthesized.…”

“…It is therefore predicted that the fire resistance of the D-GR/EP composites could be enhanced by improving the compatibility of the graphene nanohybrids and the resin matrix without affecting their mechanical and thermal performances. 31 Additionally, the influences of D-GR on the mechanical performance, thermal properties, and fire retardancy of EP were thoroughly investigated. The flameretardant mechanism of the proposed composite was clarified on the basis of the pyrolysis products and thermal degradation behaviors of D-GR/EP composites, as well as the structure and morphology of residual coke.…”

“…The treated graphene could be readily modified and integrated with the proposed phosphorus/nitrogen‐containing silane compound. It is therefore predicted that the fire resistance of the D‐GR/EP composites could be enhanced by improving the compatibility of the graphene nanohybrids and the resin matrix without affecting their mechanical and thermal performances 31 . Additionally, the influences of D‐GR on the mechanical performance, thermal properties, and fire retardancy of EP were thoroughly investigated.…”

Mechanical Characteristics of Lime-Treated Subgrade Soil Improved by Polypropylene Fiber and Class F Fly Ash

“…However, some research showed that the application of lime-treated soil caused tensile failure and serious deformation problems in some projects [ 10 , 11 , 12 ]. Hence, a great deal of materials were used by researchers to improve the limitations of lime-treated soil, and found that fibers and fly ash were better modification materials [ 13 , 14 , 15 , 16 , 17 ]. For example, some studies showed that fibers had a good effect on the tensile strength, ductility, crack resistance, and brittle failure of lime-treated soils to some extent, while that of fly ash could enhance its shear strength, bearing capacity, and deformation resistance [ 18 , 19 ].…”