Mechanical and Electrical Properties of Epoxy Composites Modified by Functionalized Multiwalled Carbon Nanotubes

Abstract

This paper investigates the effect of multiwalled carbon nanotubes on the mechanical and electrical properties of epoxy resins and epoxy composites. The research concerns multiwalled carbon nanotubes obtained by catalytic chemical vapor deposition, subjected to purification processes and covalent functionalization by depositing functional groups on their surfaces. The study included the analysis of the change in DC resistivity, tensile strength, strain, and Young’s modulus with the addition of carbon nanotubes in the range of 0 to 2.5 wt.%. The effect of agents intended to increase the affinity of the nanomaterial to the polymer on the aforementioned properties was also investigated. The addition of functionalized multiwalled carbon nanotubes allowed us to obtain electrically conductive materials. For all materials, the percolation threshold was obtained with 1% addition of multiwalled carbon nanotubes, and filling the polymer with a higher content of carbon nanotubes increased its conductivity. The use of carbon nanotubes as polymer reinforcement allows higher values of tensile strength and a higher strain percentage to be achieved. In contrast, Young’s modulus values did not increase significantly, and higher nanofiller percentages resulted in a drastic decrease in the values of the abovementioned properties.

Ultimate tensile behavior of short single‐wall carbon nanotube/epoxy composites and the reinforced mechanism

“…Usually MWCNTs have a larger diameter (2.5–50 nm) than that of SWCNTs (0.5–1.0 nm), therefore MWCNTs reinforced epoxy composites should have a higher optimal CNT content φ opt than SWCNTs/epoxy composites (Figure 7 and Figure 8B). This was confirmed by many of previous works, [ 34,36,42,43,59,60,62,71–73 ] where the optimal CNT content φ opt for MWCNTs/epoxy composites is in the range of 0.25–2.0 wt% CNTs, which is much higher than the value of 0.05 wt% SWCNTs in this work. For example, Dehghan et al used MWCNTs with a diameter of 90–130 nm and length of 20–45 μm to reinforce epoxy and found that addition of 2 wt% MWCNTs into epoxy has the highest tensile strength.…”

“…The above theoretical analyses indicate that the CNT content, radius and length all have the important influence on the tensile strength of composite, which can partly explain why the dependence of the fracture strength of composites on the CNT content is different for different works. [29,34,36,38,42,43,[59][60][61][62][63][71][72][73] CNTs used in these works were acid-treated, which actually are shortlength CNTs. However, the radius and practical length of CNTs in different works possibly are different.…”

A study on electrical properties of polymer enhancement by multiwalled carbon nanotube

“…The development of the polymer's properties may arise trough the filling process with several nano-fillers such as fibers, semiconductors, organic, metals and inorganic constituent part besides carbon constructions. Epoxy resins are thermosetting polymers and they are the largest commonly used resins [2]. They are with low molecular weight organic liquids holding epoxide groups.…”

Synergistic Enhanced Thermal Conductivity and Dielectric Constant of Epoxy Composites with Mesoporous Silica Coated Carbon Nanotube and Boron Nitride Nanosheet

“…Polymer dielectrics are extensively utilized in electronic devices because of their easy processing, flexibility, and light weight [ 1 , 2 , 3 , 4 , 5 , 6 ]. However, the low thermal conductivity of polymer dielectrics cannot meet the rising demand of efficient heat dissipation due to continues miniaturization electronic devices with high speed and high power [ 5 , 7 , 8 , 9 ]. Incorporation of thermally conductive fillers into polymer matrix is regarding as an effective strategy to improve the thermal conductivity of materials [ 10 , 11 , 12 , 13 , 14 ].…”