Simultaneously tough and conductive rubber–graphene–epoxy nanocomposites

Abstract

Abstract:In the current work the microstructure and fracture performance of carbon-fibre reinforced polymer (CFRP) composites based upon matrices of an anhydride-cured epoxy-resin (formulated with a reactive diluent), and containing silica nanoparticles and/or polysiloxane core-shell rubber (CSR) nanoparticles, were investigated. Double cantilever beam tests were performed in order to determine the interlaminar fracture energy of the CFRP composites, while the single edge-notched bend (SENB) specimen was employed to evaluate the fracture energy of the bulk polymers. The fracture energy of the bulk epoxy polymers increased from 173 J/m 2 for the unmodified polymer to a maximum of 1,237 J/m 2 with the addition of 16 wt% of CSR nanoparticles. The toughening mechanisms were identified as (a) localised plastic shear yielding and (b) cavitation of the CSR particles followed by plastic void growth of the matrix. The steadystate propagation value of the interlaminar fracture energy of the CFRP composites increased with increasing nanoparticle concentration, from 1,246 J/m 2 for the unmodified epoxy matrix to a maximum of 1,851 J/m 2 with 4 wt% of silica nanoparticles and 8 wt% of CSR particles. Crack growth in the CFRP composites was dominated by fibre-bridging toughening mechanisms. The efficiency of the transfer of toughness from the bulk polymers to the carbon fibre composites was considered. The measured fracture energy of both bulk and composite materials decreased at a test temperature of -80°C, compared with room temperature. Nevertheless, the toughening effects of both the silica and CSR nanoparticles on the bulk epoxy polymers and the CFRP composites, compared with the unmodified epoxy polymers, were still evident even at the lower temperatures. Indeed, the toughening effect of the silica nanoparticles was greater at relatively low test temperatures than at room temperature.

Synergistic toughening and electrical functionalization of an epoxy usingMWCNTsand silane‐ /plasma‐activated basalt fibers

“…Nanoscale additives, such as rubber nanoparticles, [ 1 ] silica nanoparticles, [ 6 ] graphene, [ 10 ] and carbon nanotubes (CNTs), [ 11 ] were also widely used as epoxy toughening agents. CNTs are attractive candidates as modifier materials for the toughening and modification of epoxies, due to their outstanding properties, that is, high aspect ratio of up to several thousands, excellent electrical conductivity, and high mechanical properties.…”

Nano-modified epoxy: the effect of GO-based complex structures on mechanical performance

“…17 The existing studies include the application of larger less-reactive graphite nanoplatelets (GNPs) in combination with polyethersulfone and liquid rubbers. [18][19][20] On the other hand, GO was applied for the upgradation of epoxy modied, e.g., with a sulfonated block copolymer (ionomer) 21 and polysulfone. 22,23 The high structure-directing effect, which can be accompanied by the formation of effective complex structures, can be anticipated, especially in the case of the application of polymer chain-modied CN.…”

Tertiary‐amine‐terminated polybutadiene and butadiene acrylonitrile: Synthesis and application in the modification of epoxy resins

“…Consequently, intensive research efforts have focused on seeking effective ways to toughen these cross‐linked polymers. The incorporation of a second phase, such as liquid rubbers, 9–11 thermoplastic polymers, 12,13 core‐shell particles, 14–16 fibre, 17,18 and block copolymers, 19,20 has been demonstrated significantly useful to improve the toughness of epoxy resins.…”

“…Over the past decades, the most effective modification strategy for epoxy resins has been the addition of liquid rubbers as the toughening matrix, like polybutadienes 21 and butadiene acrylonitrile 9 . The key of the toughening strategy lies in the formation of two‐phase separation sea‐island structure by the active terminal groups of liquid rubbers reacting with epoxy resins, mainly including carboxyl 22 and primary amine 23 .…”