Synthesis and properties of novel aromatic polyamides derived from 1,5‐bis(4‐aminophenoxy)naphthalene and aromatic dicarboxylic acids

Abstract

A new bis(phenoxy)naphthalene‐containing diamine, 1,5‐bis(4‐aminophenoxy)naphthalene, was synthesized in two steps from the condensation of 1,5‐dihydroxy‐naphthalene with p‐chloronitrobenzene in the presence of potassium carbonate, giving 1,5‐bis(4‐nitrophenoxy)naphthalene, followed by hydrazine hydrate/PdC reduction. A series of polyamides and copolyamides were synthesized by the direct polycondensation of the diamine with various aromatic dicarboxylic acids or with mixed dicarboxylic acids in N‐methyl‐2‐pyrrolidone (NMP) using triphenyl phosphite and pyridine as condensing agents. The polymers having inherent viscosity of 0.81–1.25 dL/g were obtained in quantitative yield. Most of the polymers were generally soluble in aprotic solvent such as N,N‐dimethylacetamide, N‐methyl‐2‐pyrrolidone, etc. The polymers derived from rigid dicarboxylic acids such as terephthalic acid, naphthalene dicarboxylic acid, and 4,4′‐biphenyldicarboxylic acid exhibited crystalline patterns. Glass transition temperatures of polymers were in the range of 230–360°C, and 10% weight loss temperatures in nitrogen and air were above 492 and 470°C, respectively. © 1993 John Wiley & Sons, Inc.

Synthesis and Properties of Fluorinated Polyamides Based on 2,7-Bis(4-amino-2-trifluoromethylphenoxy)naphthalene

“…According to a well-established procedure, [12][13][14][15][16] (mp = 172-173 • C) and 3F-BAPON (mp = 160-161 • C) were prepared by the aromatic nucleophilic substitution reaction of 2,7-dihydroxynaphthalene with p-chloronitrobenzene and 2-chloro-5-nitrobenzotrifluoride, respectively, in the presence of potassium carbonate, and subsequent reduction of the intermediate dinitro compounds using hydrazine as the reducing agent and palladium as the catalyst. The synthetic details and characterization data of the new diamine 3F-BAPON were described in a previous publication.…”

“…[3][4][5][6][7][8][9][10][11] We have demonstrated that polyamides containing bis(phenoxy)naphthalene unit such as those from 2,7-or 1,5-bis(4-aminophenoxy)naphthalene showed enhanced solubility and comparable thermal stability as compared to conventional aramids. 12,13 However, some of these modified polyamides such as that derived from 2,7-bis(4-aminophenoxy)naphthalene (BAPON) and rigid terephthalic acid were crystalline and insoluble in organic solvents. It is known that the introduction of ether linkages into the polymer backbone imparts processability and solubility to polymers without much loss of thermal stability, and the incorporation of fluorine-containing substituents is also know to enhance the solubility of aromatic polymers such as polyimides.…”

Synthesis and properties of novel aromatic polyamides derived from 2,2‐bis[4‐(4‐amino‐2‐fluorophenoxy) phenyl]hexafluoropropane and aromatic dicarboxylic acids

“…The direct polycondensation of aromatic diamines with aromatic dicarboxylic acids with triphenyl phosphite and pyridine as condensation agents is known to be a convenient method for preparing aromatic polyamides. 6,16,17 We used this method in our synthesis. The reaction scheme and the structures of the polymers are shown in Scheme 2.…”

Synthesis and Characterization of Poly(amide-imide)s Based on 1,7-Bis(4-aminophenoxy)naphthalene and Various Bis(trimellitimide)s

“…31, No. 12,1999 tinguished in the spectra. The results of elemental analysis of Series III are listed in Table II.…”