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

Abstract

A series of novel ternary conductive composites have been prepared by incorporating functionalized multiwalled carbon nanotubes (FMWCNTs) into the binary composites of poly(amide-imide) (PAI) and poly( o-methoxyaniline) (POMA) to further improve the conductivity of PAI composites. With increasing the weight ratio of FMWCNTs, the conductivity of PAI/POMA/FMWCNTs ternary composites has been significantly enhanced from 10−3 S m−1 to 90 S m−1, much higher than that of the sum of PAI/POMA and PAI/FMWCNTs binary composites. The enhanced conductivity is mainly ascribed from a much more intensive conductive network formed in the PAI/POMA/FMWCNTs ternary composites. It is found that the N–H bending of amide group in the Fourier transform infrared spectrometry spectra is observed at 3298 cm−1 for PAI, 3296 cm−1 for PAI/POMA binary composites, and further blue shifted to 3292 cm−1 for PAI/POMA/FMWCNTs ternary composites. Moreover, the glass transition temperature has been increased from 82.5°C to 117.7°C. These results suggested that the hydrogen bonding interaction has been strengthened among PAI, POMA, and FMWCNTs, which is useful for dispersion of condcutive fillers into the polymer matrix.

Obvious improvement of dispersion of multiwall carbon nanotubes in polymer matrix through careful interface design

“…The introduction of polar groups on the CNTs surface by the strong acid oxidation or by ultrasound has been confirmed to be an effective approach, but the unique 2D hexagonal graphitic lattice is inevitably damaged during the strong oxidation process, which would cause significant loss in the electronic and mechanical properties 17–22 . Another common method is to graft polymers or oligomers with structures close to the polymer matrix on the surface of CNTs, but this treatment is expensive and too complicated 23–27 …”

Design and synthesis of high-performance poly(amide-imide) for multifunctional electromagnetic interference shielding films

“…Poly (amide-imide) (PAI) has been widely used as one kind of high-performance polymers containing amide and imide groups in the main chain. [51][52][53][54][55][56][57][58][59][60][61] It is generally recognized that amide groups are useful for improving the solubility, and the aromatic imide groups are beneficial to offer good mechanical, anti-corrosion and thermal properties. In other words, PAI possess good mechanical and thermal properties of poly (imide) (PI) as well as ease of processability of poly (amides) (PA).…”