Mechanical Properties of the Carbon Nanotube Modified Epoxy–Carbon Fiber Unidirectional Prepreg Laminates

Abstract

The effect of plasma treatment of the multi-walled carbon nanotube (MWCNT) surface on the fracture toughness of an aerospace grade epoxy resin and its unidirectional (UD) carbon fiber prepreg laminates has attracted scientific interest. A prepreg route eliminates the possible risk of carbon nanotube filtration by unidirectional carbon fibers. X-ray photoelectron spectroscopy results suggested that oxygen atom concentration at the nanotube surface was increased from 0.9% to 3.7% after plasma modification of the carbon nanotubes. A low number (up to 0.5 wt.%) of MWCNTs was added to epoxy resin and their carbon fiber prepreg laminates. Transmission electron micrographs revealed that the plasma treatment resulted in a better dispersion and distribution of MWCNTs in the epoxy resin. Plasma-treated MWCNTs resulted in a more pronounced resistance to the crack propagation of epoxy resin. During the production of the reference and nanotube-modified prepregs, a comparable prepreg quality was achieved. Neat nanotubes agglomerated strongly in the resin-rich regions of laminates lowering the interlaminar fracture toughness under mode I and mode II loading. However, plasma-treated nanotubes were found mostly as single particles in the resin-rich regions of laminates promoting higher energy dissipation during crack propagation via a CNT pull-out mechanism.

Effect of Atmospheric-Pressure Plasma Treatments on Fracture Toughness of Carbon Fibers-Reinforced Composites

“…It has a chemically stable molecular structure due to its high strength and cross-linked density, which are inherent properties of epoxy resins. However, this means that the resistance to impact resistance, crack propagation, and brittleness is insufficient [ 8 , 9 , 10 , 11 ]. In addition, problems in the area of critical cracking are limited in various industrial applications [ 12 , 13 , 14 , 15 ].…”

Double-Decker-Shaped Polyhedral Silsesquioxanes Reinforced Epoxy/Bismaleimide Hybrids Featuring High Thermal Stability

“…Nonetheless, conventional epoxy resin cannot meet the requirements for thermal or flame resistance, and thus high thermal stability polymers such as poly(ether imide) or poly(ether sulfone) have been used in epoxy resin to enhance this property [7][8][9][10]. Furthermore, nanomaterials such as polyhedral oligomeric silsesquioxane (POSS), clay, or graphene have also been reported as viable modifications to the epoxy matrix because these inorganic materials usually possess a higher thermal stability than organic polymers [11][12][13][14][15][16].…”

Clarifying the chemical reactions of the weakening of adhesion between epoxy resin and aluminum by molecular dynamic simulation and experiment

“…Epoxy resin has excellent mechanical, electrical, thermal and bonding properties, and is widely used in coatings (Zhang et al, 2015;Waskiewicz et al, 2013;Langer et al, 2019), electronic product packaging (Komoda, 2013;Feng et al, 2018;Li et al, 2019), aerospace (Fischer et al, 2011;Bakis et al, 2021) and electrical equipment (Ramu and Nagamani, 2014;Wang et al, 2019). Because gas-insulated transmission line (GIL) has the advantages of large transmission capacity, low power loss, flexible laying and good reliability, it is suitable for special areas with harsh natural environment and large height drop (Xiao and Yan 2017;Magier et al, 2018).…”