Synthesis of hyperbranched aromatic polyamide–imide and its grafting onto multiwalled carbon nanotubes

Abstract

A flexible hyperbranched aromatic polyamide-imide (PAI) having an amine group in the center and carboxyl groups in the ends was synthesized from a AB 2 type of monomer of 2-(6-aminohexylcarbomoyl) terephthalic acid that was prepared from trimellitic anhydride and 1,6-diaminohexane. Fourier transformed infrared spectra (FTIR), NMR, and ES-MS were used to characterize the structure of the monomer and the synthesized hyperbranched polymer. Then the hyperbranched PAI was grafted onto the multiwalled carbon nanotubes (MWNTs) that was first treated by acid and changed into MWNTCOCl by SOCl 2 in a tetrahydrofuran solution. By observation with transmission electron microscopy and characterization with FTIR and thermal gravity of analysis, the functionalized MWNTs were terminally enclosed with polymer; it was believed that the MWNTs were linked with a big carboxylic claw at the end and the adsorption ability of the MWNTs to NH 2 -substrate was enhanced.

Core-shell Structured Hyperbranched Aromatic Polyamide/BaTiO3 Hybrid Filler for Poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene) Nanocomposites with the Dielectric Constant Comparable to That of Percolative Composites

“…The final step for preparing BT-HBP is to grow a layer of hyperbranched aromatic polyamide on the surface of the BT nanoparticles. Hyperbranched aromatic polyamide is highly branched macromolecule with three-dimensional spherical architecture and is considered as a fine coating agent of nanoparticles. − It can be prepared by either homo- or copolymerization of ABx building blocks or by copolymerization of Ax and By type monomers . In this contribution, direct polycondensation of 3, 5-diaminobenzoic acid was employed.…”

Surface modification of carbon nanotubes with dendrimers or hyperbranched polymers

“…52,53 In most cases, by amidation or esterification reaction with the carboxylic acid groups or derivated acid chloride groups on CNTs surface, polymer chains terminated with amino or hydroxyl moieties are attached. [54][55][56][57][58][59][60][61][62] In addition, as an efficient coupling reaction, ''click'' chemistry is exploited in the approach of grafting dendritic polymers onto CNTs. Although the ''grafting to'' method has the limitation of a relative low grafting density and demands the reactive groups for polymers, it is proved to be a facile and reliable approach to surface modification of CNTs.…”

Functionalization of Carbon Materials using the Diels‐Alder Reaction

“…These methods have been extensively reviewed. [14] In most of the cases, a series of reactions is necessary for the final attachment of polymer chains on the carbon nanofiller surfaces [15][16][17] and harmful chemicals are required (e.g. thionyl chloride).…”