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A novel, fluorinated diamine monomer, 2,5-bis(4-amino-2-trifluoromethylphenoxy)-tert-butylbenzene (II) was synthesized through the nucleophilic substitution reaction of tert-butylhydroquinone (t-BHQ) and 2-chloro-5-nitrobenzotrifluoride in the presence of potassium carbonate to yield the intermediate dinitro compound I, followed by catalytic reduction with hydrazine and Pd/C to afford diamine II. A series of fluorinated polyimides V were prepared from II with various aromatic dianhydrides (III a-f ) via the thermal imidization of poly(amic acid). Most of V a-f could be soluble in amide-type solvents and even in less polar solvents. These polyimide films showed tensile strengths up to 106 MPa, elongation at break up to 21%, and initial modulus up to 2.1 GPa. The glass-transition temperature of V was recorded at 245-304°C, the 10% weight loss temperatures were above 488°C, and left more than 41% residue even at 800°C in nitrogen. Low dielectric constants, low moisture absorptions, and higher and light-colored transmittances were also observed.

A novel, fluorinated diamine monomer with the ether–ketone group, 4,4′‐bis(4‐amino‐2‐trifluoromethylphenoxy)benzophenone (2), was prepared through the nucleophilic substitution reaction of 2‐chloro‐5‐nitrobenzotrifluoride and 4,4′‐dihydroxybenzophenone in the presence of potassium carbonate, followed by catalytic reduction with hydrazine and Pd/C. Flourinated polyimides (PIs) 5a–f and copolyimides (co‐PIs) 5c/a–f were synthesized from 2 and various commercial aromatic dianhydrides via thermal or chemical imidization. PIs 5a–f had inherent viscosities ranging from 0.72 to 1.22 dL/g. Besides the chemical imidization of 5c(C), the 5(C) series were soluble in amide‐type solvents and even in less polar solvents, but PIs 5a–f prepared via thermal imidization were insoluble. PI films 5a–f exhibited tensile strengths ranging from 92 to 112 MPa, elongations at break from 8 to 15%, and initial moduli from 2.0 to 2.1 GPa. The glass‐transition temperatures of the 5 series were in the range of 232–278 °C, and the 10% weight‐loss temperatures were above 535 °C, with more than a 50% char yield at 800 °C in nitrogen. In comparison of the PI 5 series with the analogous non‐fluorinated PIs 6 series based on 4,4′‐bis(4‐aminophenoxy)benzophenone, the 5 series revealed better solubility, lower color intensity, dielectric constant, and moisture absorption. Their PI films had cutoff wavelengths between 370 and 410 nm, b* values ranging from 9.6 to 58.3, dielectric constants of 3.05–3.64 (1 MHz), with moisture absorption in the range of 0.08–0.38 wt %. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 222–236, 2004

A novel series of colorless and highly organosoluble poly(ether imide)s were prepared from 3,3-bis [4-(3,4-dicarboxyphenoxy)phenyl]phthalide dianhydride with various fluorinated aromatic bis(ether amine)s via a conventional two-stage process that included ring-opening polyaddition to form the poly(amic acid)s followed by cyclodehydration to produce the polymer films. The poly(ether imide)s showed excellent solubility, with most of them dissoluble at a concentration of 10 wt % in amide polar solvents, in ether-type solvents, and even in chlorinated solvents. Their films had a cutoff wavelength between 358 and 373 nm, and the yellowness index ranged from 3.1 to 9.5. The glass-transition temperatures of the poly(ether imide) series were recorded between 237 and 297 8C, the decomposition temperatures at 10% weight loss were all above 494 8C, and the residue was more than 54% at 800 8C in nitrogen. These films showed high tensile strength and also were characterized by higher solubility, lighter color, and lower dielectric constants and moisture absorption than an analogous nonfluorinated polyimide series. a L* indicates lightness. A positive a* values means red, whereas a negative a* value indicates green. A positive b* value means yellow, whereas a negative b* value implies blue. b 8c, 8f, and 8g were derived from 6FDA and diamine 4. c 3148 YANG AND SU