Preparation and properties of novel soluble aromatic polyimides from 4,4′‐diaminotriphenylamine and aromatic tetracarboxylic dianhydrides

Abstract

New aromatic polyimides containing triphenylamine unit were prepared by two different methods, i.e., a conventional two‐step method starting from 4,4′‐diaminotriphenylamine and aromatic tetracarboxylic dianhydrides and the one‐step thioanhydride method starting from the aromatic diamine and aromatic tetracarboxylic dithioanhydrides. Both procedures yielded high‐molecular‐weight polyimides with inherent viscosities of 0.47–1.17 dL/g. Some of these polymers were soluble in organic solvents such as N,N‐dimethylacetamide, N‐methyl‐2‐pyrrolidone, m‐cresol, and pyridine. All the polyimides afforded transparent, flexible, and tough films, and the color varied from pale yellow to dark red, depending markedly on the tetracarboxylic acid components. The glass transition temperatures (Tgs) of these polyimides were in the range of 287–331°C and the 10% weight loss temperatures were above 520°C in air. The polyimides prepared by the one‐step method exhibited better solubility in organic solvents and had somewhat lower Tgs than the polymers prepared by a conventional two‐step method.

Synthesis and Characterization of Polyimide from 4,4’-Diamino diphenyl ether having Substituents at 2,2’-position

“…Their one major drawback is that they are insoluble in organic solvents and unprocessable after conversion from polyamic acid, the precursor of polyimide, to the polyimide form. One attractive method to improve solubility is the introduction of bulky phenyl group into the polyimide backbone, and a number of organic soluble polyimides have been successfully prepared without decreasing the thermal properties [2][3][4][5]. We have prepared aromatic polyimides from a diamine monomer, 1 and 2, which had phenyl and trifluoromethy groups at the 2-and 2'-position of the diphenyl ether moiety, respectively, and compared the properties with those of the corresponding 4, 4'-oxydianiline-based polyimides without phenyl group [6][7][8].…”

Synthesis and characterization of new thermally stable poly(ether-imide)s derived from 4-aryl-2,6-bis[4-(3-nitrophthalimido)phenyl] pyridines

“…[1][2][3][4]. Four different diamines, namely 4-phenyl-2,6-bis(4-aminophenyl)pyridine (DA 1 ), 4-(4-methylphenyl)-2,6-bis(4-aminophenyl)pyridine (DA 2 ), 4-(4-chlorophenyl)-2,6-bis(4-aminophenyl)pyridine (DA 3 ) and 4-(4-methoxyphenyl)-2,6-bis(4-aminophenyl)pyridine (DA 4 ) were synthesized according to the procedure described in one of our previous papers (Scheme 1) [37].…”

“…The other 15 poly(ether-imide)s (PEI [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] ) were prepared by the same procedure using appropriate dinitrobisimides and four different aromatic diols (DO 1-4 ). All synthesized polymers were characterized by FT-IR and 1 H-NMR spectroscopy ( Table 2).…”

“…In continuation of our studies on synthesis and characterization of processable polyimides [15], polyamides [37], polyesters [38] and polyureas [39], here the synthesis and characterization of new dinitrobisimide monomers from the reaction of 4-aryl-2,6-bis(4-aminophenyl)pyridines (DA [1][2][3][4] ) and 3-nitrophthalic anhydride, and related thermally stable poly(ether-imide)s are described. All monomers, model compounds and polymers were characterized and physical properties of these polymers, including inherent viscosity, solubility behavior, thermal properties and thermal stabilities, were studied.…”

Synthesis and Characterization of Some New Thermally Stable Crystalline Polyamides and Co-Polyamides Bearing Bipyridine Side-Chain Groups

“…However, the processing of these polymers by thermoplastics methods has been extremely difficult because in many cases they do not melt below their decomposition temperature and moreover they are insoluble in organic solvents [8][9][10][11]. The need for engineering plastics overcoming these problems recently increased and to make aromatic polyamides more processable, various attempts have been made to reduce their melting temperature or improve their solubility, such as incorporation of flexible linkages [12][13][14], using molecular asymmetry [15][16][17] and incorporation of bulky pendant groups [18][19][20] into the backbone.…”