Polychlorinated polyamides. II. Synthesis and characterization of polyamides derived from 2, 5‐dichloroterephthaloyl dichloride and perchloroterephthaloyl dichloride

Abstract

New thermally stable polyamides were prepared by interfacial polymerization of the title compounds and various aliphatic and aromatic diamines. The polymers were characterized by infrared spectrometry, elemental analysis, and differential scanning calorimetry. The molecular weights of the polymers were estimated by viscosity measurements. The influence of the halogen content on the thermal properties and degree of polymerization of the polymers was studied. One of the polyamides was fractionated to determine the degree of polydispersity.

Novel phenyl-substituted aromatic polyamides

“…In this paper we report that the reaction of both PBTB (2) and PBTAB (3) with bromine vapor depends on the phase (solid-gas versus solution-gas), and the product of either reaction condition is not the simple dehydrogenated product reported before but a brominated material containing covalently bonded as well as ionic halogen. Once the bromination product of 2 is reduced with hydrazine to remove the dopant bromide, it exhibits a bandgap of 1.53 eV (presumably dehydrogenated, partially brominated material) and not 0.83 eV as claimed before.…”

“…Full details of the monomer synthesis and polymerization procedures will be given in the next publication. In a series of papers dealing with a clever way to implement current theoretical models for the design of degenerate ground-state conducting polymers, it was claimed that polymers [1][2][3][4] could be dehydrogenated by treatment with bromine vapor to low-gap polymeric semiconductors with Eg as low as 0.75 eV.1-3 The bromination of thin films was followed by electronic and FTIR spectroscopy but no NMR experiments nor elemental analyses were mentioned.2,3 It was also concluded that since there were no peaks due to C-Br stretching in the 500-650-cm-1 region, no electrophilic substitution had taken place. The products were postulated to have the general structures 1A-4A1 and more specifically structure 3A2,3 shown below.…”

Synthesis and properties of new halogen-substituted polyamides from 5-halo-m-phenylenediamines and both aliphatic and aromatic dicarboxylic acids

“…Actually, several authors have reported the synthesis and characterization of halogen-containing polyamides from chloro-substituted and bromo-substituted aromatic dicarboxylic acids [1][2][3][4][5][6][7] or halogenated aromatic diamines, [7][8][9][10][11][12][13][14] where chloro-substituents and bromo-substituents were incorporated, in most cases, on the aromatic ortho position to the amide linkage. Pearce et al [11][12][13][14] reported that the high flame retardancy of the polyamides substituted with halogens in the ortho position to the NH group was attributable to intramolecular cyclization that gave benzoxazole rings and enhanced crosslinking as well.…”

Preparation and properties of aromatic polyamide homologs containing chlorine substituents

“…The introduction of halogen groups onto the aromatic nucleus of a para‐oriented aromatic polyamide has been suggested as a possible method capable of improving both solubility and inflammability of the resultant polymer products 20–24. However, it has been indicated that the halogenated PPTA exhibits lower thermal stability due to two‐step decomposition behavior to yield lower char residue 14–16, 18…”