Mechanical, Electrical, and Thermal Properties of Carbon Nanotube Buckypapers/Epoxy Nanocomposites Produced by Oxidized and Epoxidized Nanotubes

Abstract

High volume fraction carbon nanotube (CNT) composites (7.5–16% vol.) were fabricated by the impregnation of CNT buckypapers into epoxy resin. To enhance the interfacial reaction with the epoxy resin, the CNTs were modified by two different treatments, namely, an epoxidation treatment and a chemical oxidation. The chemical treatment was found to result in CNT length severance and to affect the porosity of the buckypapers, having an important impact on the physico-mechanical properties of the nanocomposites. Overall, the mechanical, electrical, and thermal properties of the impregnated buckypapers were found to be superior of the neat epoxy resin, offering an attractive combination of mechanical, electrical, and thermal properties for multifunctional composites.

Multi-Functional Properties of MWCNT/PVA Buckypapers Fabricated by Vacuum Filtration Combined with Hot Press: Thermal, Electrical and Electromagnetic Shielding

“…As a result, the densification of the CNT networks caused by the hot press at 70 °C played a crucial role in improving the thermal conductivities, promoting 2.473 W/m·k. A similar conclusion was reached in the study by Trakakis [ 46 ], where it was found that the thermal conductivity increased with decreasing porosity. In addition, the thermal conductivity of composites reinforced by CNTs was affected by many factors, such as defects, phonon scattering, filler type, structure, functionalization, alignment, and network formation [ 47 ].…”

Fabrication, Functionalization, and Application of Carbon Nanotube-Reinforced Polymer Composite: An Overview

“…The prepreg was compression-molded using a hydraulic press. Since prepregs have become the main raw materials in the composites industry, this technique can be applied in composites science and technology for new materials with a combination of tailored mechanical, electrical, and thermal properties [ 100 , 101 ].…”

“…The introduction of CNTs into a polymer matrix lowers the percolation threshold because the nanotubes are covalently incorporated into the polymer cross-linked structure. This network structure of fillers create conductive paths where the CNTs are in close contact to each other, thus facilitating the conduction of electron through ‘hopping’ or ‘tunnelling’ mechanisms [ 100 ]. Therefore, with increased volume fractions of CNTs, the network paths intensify and hence abruptly increase the conductivity of reinforced polymer matrices.…”

“…Bucky paper offers a wide range of features that are capable of reinforcing existing multifunctional applications or invented new ones. Through this method, epoxy resin can be enhanced to become a high performance materials comparable to that glass fiber/epoxy composites with various properties including electrical insulation, semiconduction, thermal insulation, and thermal conduction [100]. An approach to making bucky paper-based phenolic resin composites was reported by Teotia et al (2014) [101].…”

“…The dispersion constructed electrically-conductive networks with an ultralow percolation threshold of 0.056 vol.%, which led to a significantly high electrical conductivity at 2.8 Sm −1 at a relatively low CNT concentration of 0.85 vol.%. Moreover, with the aim to improve the epoxy resin's electrical performance, Trakakis et al (2020) [100] produced CNT/epoxy nanocomposites using the bucky papers approach. This approach allowed for better CNTs dispersion into the matrix with longer CNTs, which improved the total conductivity of the nanocomposites.…”