Electromagnetic, Morphological, and Electrical Characterization of POMA/Carbon Nanotubes-Based Composites

Abstract

This study involves the preparation of conducting composites based on poly(o-methoxyaniline) (POMA) and carbon nanotubes (CNT) and the evaluation of them as radar absorbing materials (RAM), in the frequency range of 8.2–12.4 GHz (X-band). The composites were obtained by synthesis in situ of POMA in the presence of CNT (0.1 and 0.5 wt% in relation to the o-methoxyaniline monomer). The resulting samples—POMA/CNT-0.1 wt% and POMA/CNT-0.5 wt%—were incorporated in an epoxy resin matrix in the proportion of 1 and 10 wt%. FT-IR analyses show that the POMA was successfully synthesized on the CNT surface. SEM analyses show that the synthesized POMA recovered all CNT surface. Electrical conductivity measurements show that the CNT contributed to increase the conductivity of POMA/CNT composites (1.5–6.7 S·cm−1) in relation to the neat POMA (5.4 × 10−1 S·cm−1). The electromagnetic characterization involved the measurements of complex parameters of electrical permittivity (ε) and magnetic permeability (µ), using a waveguide in the X-band. From these experimental data reflection loss (RL) simulations were performed for specimens with different thicknesses. The complex parameters show that the CNT in the composites increased ε and µ. These results are attributed to the CNT network formation into the composites. Simulated RL curves of neat POMA and POMA/CNT in epoxy resin show the preponderant influence of POMA on all RL curves. This behavior is attributed to the efficient CNT recovering by POMA. RL results show that the composite based on 10 wt% of POMA/CNT-0.5 wt% in epoxy resin (9 mm thickness) presents the best RL results (≈87% of attenuation at 12.4 GHz).

Conductivity enhancement of poly(amide-imide) composites based on the synergistic effect of poly(o-methoxyaniline) and functionalized multiwalled carbon nanotube

“…[42][43][44] Moreover, it has been reported that POMA and CNTs played a synergistic effect in conductivity, with incorporation 10 wt% of CNT into POMA, the conductivity of the hybrid conductive fillers POMA/CNT was improved by one order of magnitude. 45 Therefore, with good compatibility and synergistic effect of POMA and CNT, POMA and CNT would be an efficient combination to improve the conductivity of polymer composites.…”

The Effect of High Loaded Multiwall Carbon Nanotubes in Natural Rubber and Their Nonlinear Material Constants

“…Takeuchi et al [15] reported that the reinforcing performance improves as diameter of MWCNT decreases, while thermal resistance improves as heat-treatment temperature decreases. Pinto and Rezende [16] prepared a conducting composite with poly(o-methoxyaniline) (POMA) and CNT of 0.1 and 0.5 wt% and incorporated them in epoxy resin. They concluded that inclusion of CNTs increased the conductivity of the composite.…”