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Syntheses and properties of aromatic polyamides and polyimides derived from 9,9‐bis[4‐( p ‐aminophenoxy)phenyl]fluorene

1993; Wiley; Volume: 31; Issue: 8 Linguagem: Inglês

10.1002/pola.1993.080310821

1099-0518

Chin‐Ping Yang, Jiun‐Hung Lin,

Tribology and Wear Analysis

Abstract 9,9‐Bis[4‐( p ‐aminophenoxy)phenyl]fluorene ( II ) was used as a monomer with various aromatic dicarboxylic acids and tetracarboxylic dianhydrides to synthesize polyamides and polyimides, respectively. The diamine II was derived by a nucleophilic substitution of 9,9‐bis(4‐hydroxyphenyl)fluorene with p ‐chloronitrobenzene in the presence of K 2 CO 3 and then hydro‐reduced. Polyamides IV a‐g having inherent viscosities of 0.73–1.39 dL/g were prepared by the direct polycondensation of the diamine II with various aromatic diacids using triphenyl phosphite and pyridine as condensing agents. All the aromatic polyamides were amorphous and readily soluble in various polar solvents such as N,N ‐dimethylacetamide, N,N ‐dimethylformamide, dimethylsulfoxide, and N ‐methyl‐2‐pyrrolidone. Transparent and flexible films of these polymers could be cast from the DMAc solutions. These aromatic polyamides had glass transition temperatures in the range of 283–309°C and 10% weight loss occurred up to 460°C. The polyimides were synthesized from diamine II and various aromatic dianhydrides via the two‐stage procedure that included ring‐opening poly‐addition in DMAc to give poly(amic acid)s, followed by thermal or chemical conversion to polyimides. The poly(amic acid)s had inherent viscosities of 0.62–1.78 dL/g, depending on the dianhydrides. Most of the aromatic polyimides obtained by chemical cyclization were found to be soluble in NMP. These polyimides showed almost no weight loss up to 500°C in air or nitrogen atmosphere. © 1993 John Wiley & Sons, Inc.