Effect of seawater ageing on interlaminar fracture toughness of carbon fiber/epoxy composites containing carbon nanofillers

Abstract

This work reports the influence of seawater ageing on the mode I and mode II interlaminar fracture toughness ([Formula: see text] and [Formula: see text]) of prepreg-based unidirectional carbon fiber/epoxy laminates containing carbon nanofillers. Double cantilever beam and end notched flexure specimens were fabricated from composite laminates containing multiwalled carbon nanotubes and/or reduced graphene oxide at their middle plane interface. Experimental results showed that the addition of carbon nanofillers moderately increased the [Formula: see text] and [Formula: see text] propagation of composite laminates before and after their immersion in seawater with respect to the reference laminate under dry condition. For double cantilever beam and end notched flexure specimens aged in seawater, it was observed that [Formula: see text] and [Formula: see text] increased by 57% and 13% for specimens with multiwalled carbon nanotube/reduced graphene oxide hybrid combination, 39% and 4% for specimens with multiwalled carbon nanotubes and 53% and 8% for specimens with reduced graphene oxide respectively, as a consequence of the plasticization effect of seawater immersion on the matrix. Fracture surface examination by scanning electron microscopy revealed interlaminar failure associated to mode I and mode II delamination and toughening mechanisms produced by the multiwalled carbon nanotubes and reduced graphene oxide at delaminated regions of composite laminates.

Low‐velocity impact behavior of glass fiber‐MWCNT/polymer laminates exposed to seawater and distilled water aging

“…In the case of composite laminates containing MWCNTs (Figure 3B,D), no further change is appreciated in all the moisture absorption curves with respect to samples without MWCNTs (Figure 3A,C), which may be attributed to the poor chemical interaction between CNTs and water molecules due to the fact that the MWCNTs were used as‐received without a further chemical oxidation that provides polar oxygen functional groups on the CNT surface. Similar observations were reported for prepreg‐based carbon fiber/epoxy composite laminates modified with MWCNTs in Reference .…”

“…The selection of this aging temperature (60°C) was based on a value below the glass transition temperature of the laminate as recommended in Reference . The artificial SW preparation process can be found in our previous work . The moisture absorption content ( M t ) of composite laminates can be calculated using the following equation: where W 0 is the initial weight of the specimen before immersion and W t is the weight of the specimen at immersion time t .…”

Study of seawater effect on the mechanical and thermomechanical properties of hybrid multiwall carbon nanotube/graphene nanoplatelet‐glass fiber/epoxy laminates

“…[ 30 ] Other authors have reported that seawater aging in general affects the flexural and impact properties of GFRP composites with MWCNTs [ 23,24 ] and the creep lifetime of graphene oxide embedded GFRPs. [ 31 ] It has been recently shown that the effective mixture of CNS (CNTs and GNPs) results in hybrid CNS with three‐dimensional structures, which provides a synergistic effect on the physical and mechanical properties of polymer nanocomposites, [ 32–35 ] GFRPs, [ 36,37 ] carbon fiber reinforced polymers, [ 38–42 ] and fiber metal laminates. [ 43 ] However, there is no research work that reports the incorporation of hybrid combinations of CNTs and GNPs to the GFRP laminates by spray coating technique and evaluates its effect on the mechanical and thermomechanical properties under a hydrothermal environment like seawater aging.…”

A Green and Easy Large Scale Method for Obtaining Graphene Nanoplatelets by Steam Explosion and Ultrasonic Exfoliation

“…Graphene is a carbon allotrope, which consists of only a single atomic layer of sp 2 hybridized carbons. Graphene is one of the most interesting material around the world owing to its unique and exceptional properties such as high electrical and thermal conductivity, optical properties, large specific surface area (2630 m 2 /g), chemical properties, [1,2] high tensile strength (130 GPa) and high Young's modulus (0.5–1 TPa) [3] . These properties make this material very attractive for the development of a large amount of applications and products to industrial level, like composites materials [4,5] …”