Synthesis and Characterization of Aromatic Polyimides containing Trifluoromethyl Group from Bis(4-amino-2-trifluoromethylphenyl)ether and Aromatic Tetracarboxylic Dianhydrides

Abstract

Aromatic polyimides, which had trifluoromethyl group at 2,2 1 -position of the diphenyl ether, were synthesized from bis(4-amino-2-trifluoromethylphenyl)ether (1) and previously prepared tetracarboxylic dianhydrides, 3,3 111 ,4,4 111 -p-quaterphenyltetracarboxylic dianhydride (2d), 3,3 1111 ,4,4 1111 -p-quinquephenyltetracarboxylic dianhydride (2e) and 3,3 11111 ,4,4 11111 -p-sexiphenyltetracarboxylic dianhydride (2f), and the properties were compared than those of corresponding polyimides from commercially available tetracarboxylic dianhydrides. The polyimides were synthesized by the conventional two-step procedure of ring-opening polyaddition in N-methyl-2-pyrrolidinone (NMP) and subsequent thermal cyclic dehydration. The polyimides were characterized by differential scanning calorimetry (DSC), thermogravimetry, and dynamic mechanical analysis (DMA). The polyimides showed excellent thermal stability, and had glass transition temperature (T g ) at 234-300 2 C. The properties of polyimides were compared with those of previously prepared polyimides, which had phenyl group at 2,2 1 -position of the diphenyl ether, and the effect of the trifluoromethyl groups at the 2, 2 1 -positions of the diphenyl ether were observed in the thermal properties, solubility and optical properties of polyimides.

Synthesis and properties of polyimides from 1,4-bis(4-amino-2-phenylphenoxy) benzene and 4,4′-bis(4-amino-2-phenylphenoxy) biphenyl

“…Yield: 21.39 g (53% 4,4 0 -Bis(4-nitro-2-phenylphenoxy) biphenyl (5). In a flask, a mixture of 4.65 g (25 mmol) of 4,4 0 -dihydroxybiphenyl, 11.95 g (55 mmol) of 4-fluoro-3-phenyl nitrobenzene, 7.59 g (55 mmol) of potassium carbonate and 150 mL of DMF was stirred at 130 C for 12 h. The reaction mixture was cooled at 80 C, and the solvent was evaporated under a reduce pressure of 15-25 Torr. After the residue was washed with 250 mL of water, the pure 5 was obtained by recrystallization from 2-(2-methoxyethoxy) ethanol.…”

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

“…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]. The presence of the substituents had an influence on the solubility, and almost all the polyimides, even the polyimide from rigid 3,3'''',4,4''''-p-quinquephenyltetracarboxylic dianhydride, were soluble in organic solvents such as…”

Synthesis and characterization of organosoluble and transparent polyimides derived from trans‐1,2‐bis(3,4‐dicarboxyphenoxy)cyclohexane dianhydride

“…The diamines, m ‐BAPS, TPEQ, and TPER, were recrystallized from ethanol before use. Bis(4‐amino‐2‐trifluoromethylphenyl)ether (TFODA) and 2,2′‐bis[4‐(4‐amino‐2‐trifluoromethylphenoxy)phenyl]sulfone (6F‐BAPS) were synthesized in our laboratory according to the literature . Dimethylformamide (DMF) was purified by distillation under reduced pressure over calcium hydride and stored over 4 Å molecular sieves.…”