Electrical and thermal characteristics of MWCNTs modified carbon fiber/epoxy composite films

Abstract

To enhance interfacial bonding between carbon fibers and epoxy matrix, the carbon fibers have been modified with multiwall carbon nanotubes (MWCNTs) using the dip-coating technique. FT-IR spectrum of the MWCNTs shows a peak at 1640 cm −1 corresponding to the stretching mode of the C=C double bond which forms the framework of the carbon nanotube sidewall. The broad peak at 3430 cm −1 is due to O-H stretching vibration of hydroxyl groups and the peak at 1712 cm −1 corresponds to the carboxylic (C=O) group attached to the carbon fiber. The peaks at 2927 cm −1 and 2862 cm −1 are assigned to C-H stretching vibration of epoxy produced at the defect sites of acid-oxidized carbon fiber surface. SEM image shows a better interface bonding between the fiber and the matrix of modified composites (MWCNTs-CF/Ep) than those of unmodified composite. The loss factor curve of CF-MWCNTs/Ep composites is the narrowest compared with neat epoxy and CF/Ep composites which evinces that the length distribution range of molecular chain segments in the matrix is the narrowest. From the dependence of the AC conductivity on temperature, we can see that σ AC increases when temperature increases. The increase in electrical conductivity of the composites may be a result of the increased chain ordering due to annealing effect. The use of MWCNTs to modify the surface of carbon fiber resulted in a large amount of junctions among MWCNT causing an increase in the electrical and thermal conductivity by forming conducting paths in the matrix. The MWCNTs-CF/Ep composite shows better thermal stability than unmodified composites. The strong interaction between CF and MWCNTs can retard diffusion of small molecules from the resin matrix at high temperature and hence, result in the improved thermal stability of the modified CF/Ep composite.

Fabrication and Characterization of High-Performance Crosslinked PVA/ PMDA Doped with H2SO4

“…Polymer electrolytes were commonly researched. Unfortunately, those polymer electrolyte types have exhibited low electrode-electrolyte contact or insufficient mechanical stability, thus, were deprived of the general efficiency [7]. In order to improve ionic conductivity of the PVA film, sulfuric acid was used as sulfonating as well as cross-linking agent [8].…”

Molecular dynamics simulation on the crystallization behavior of cyclic polyethylene affected by functionalized carbon nanotubes

“…The MSD curves of C‐PE in C‐PE/CNT system are slightly lower than that of pure C‐PE, because the adsorption force of the CNT on C‐PE affects the mobility of chain segments to a certain extent 26 . Similarly, it has been reported that the presence of strong interactions in MWCNTs modified carbon fiber/epoxy composite (MWCNTs‐CF/Ep) can restrict molecular motion in the experiment 47 . The MSD values of C‐PE in the CNT‐ g ‐PE system are significantly less than that of the other two systems.…”

“…26 Similarly, it has been reported that the presence of strong interactions in MWCNTs modified carbon fiber/epoxy composite (MWCNTs-CF/Ep) can restrict molecular motion in the experiment. 47 The MSD values of C-PE in the CNT-g-PE system are significantly less than that of the other two systems. This result indicates that the addition of the CNT-g-PE considerably reduced the movement capability of the C-PE chains.…”

Anticorrosion performance of polyaniline/clay nanocomposites in epoxy coatings

“…They not only possess outstanding processability but also exhibit excellent adhesiveness and weather resistance. [7][8][9][10] In addition, the coating process is environmentally friendly and chemically stable with low volatility. 11,12 Furthermore, the addition of intrinsically conducting polymer (ICP) nanofillers, such as polyimide, polypyrrole, polythiophene, and polyaniline (PANI), to epoxy coatings can remarkably improve the anticorrosion properties.…”

“…Among the available anticorrosive techniques, epoxy coating systems are the most common type of protective coating. They not only possess outstanding processability but also exhibit excellent adhesiveness and weather resistance 7–10 . In addition, the coating process is environmentally friendly and chemically stable with low volatility 11,12 .…”