Improved Mechanical and Moisture-Resistant Properties of Woven Hybrid Epoxy Composites by Graphene Nanoplatelets (GNP)

Abstract

This research investigated the effect of adding different wt.% (0, 0.25, 0.50, and 0.75) of GNP (graphene nanoplatelets) to improve the mechanical and moisture resistant properties of Kevlar (K)/cocos nucifera sheath (CS)/epoxy hybrid composites. The laminates were fabricated with different K/CS weight ratios such as 100/0 (S1), 75/25 (S2), 50/50 (S3), 25/75 (S4), and 0/100 (S5). The results revealed that the addition of GNP improved the tensile, flexural, and impact properties of laminated composites. However, the optimal wt.% of GNP varies with different laminates. A moisture diffusion analysis showed that the laminates with a 0.25 wt.% of GNP content efficiently hindered water uptake by closing all the unoccupied pores inside the laminate. Morphological investigations (SEM and FE-SEM (Field Emission Scanning Electron Microscope)) proved that the addition of GNP improved the interfacial adhesion and dispersion. Structural (XRD and FTIR) analyses reveals that at 0.25 wt.% of GNP, all the hybrid composites showed a better crystallinity index and the functional groups presents in the GNP can form strong interactions with the fibers and matrix. A statistical analysis was performed using One-way ANOVA, and it corroborates that the mechanical properties of different laminates showed a statistically significant difference. Hence, these GNP-modified epoxy hybrid composites can be efficiently utilized in load-bearing structures.

Effects of Nanoclay on Mechanical and Dynamic Mechanical Properties of Bamboo/Kenaf Reinforced Epoxy Hybrid Composites

“…This will lead to lower mechanical properties performance. Similar observations were also reported by [ 14 , 27 ]. The microstructure studies on the interaction and distribution of the nanoclays and epoxy resin are supported with the outcome of the results from our previous work [ 25 , 28 ].…”

“…MMT has an aspect ratio ranging from 100 to 1000 [ 31 ], while HNT possesses an aspect ratio from 10 to 50 [ 32 ]. The improvement of flexural strength and modulus can be explained by the large aspect ratio of nanoclay, which is able to fill up the gaps between the reinforcing fibers matrix [ 27 ], thus reducing the void content which can behave as the weak spot of the composites. The presence of organically-modified MMT is known to improve the interfacial adhesion strength between epoxy matrix, bamboo, and kenaf fibers leading to improved interfacial bonding of the hybrid nanocomposites.…”

Synergistic Effects of Graphene/Carbon Nanotubes Hybrid Coating on the Interfacial and Mechanical Properties of Fiber Composites

“…The CF/PEEK composites with graphene oxide plus PEI complex sizing have an enhancement of interfacial shear strength. The graphene oxide sheet can block the initial cracks and reduce the stress intensity factors at the crack tips [30]. Recently our group has [21,31] used GnPs/epoxy sizing as a function coating to modify the surface of CF.…”

Preparation, characterization and performance evaluation of wood flour/HDPE foamed composites reinforced with graphene nanoplatelets

“…The second reason is that nano-sized GNPs restrict intermolecular movements of the surrounding polymer matrix thus, making water penetration into the composite much more difficult. 32–34…”