Synthesis and characterization of novel fluorinated polyimides derived from 4,4′-[2,2,2-trifluoro-1-(3-trifluoromethylphenyl)ethylidene]diphthalic anhydride and aromatic diamines

• Published in: Journal of polymer science. Part A, Polymer chemistry Vol. 42; no. 17; pp. 4143 - 4152
• Main Authors: Yang, S. Y., Ge, Z. Y., Yin, D. X., Liu, J. G., Li, Y. F., Fan, L.
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01-09-2004; Wiley
• Subjects: Applied sciences; electrical properties; Exact sciences and technology; fluorinated dianhydride; Organic polymers; Physicochemistry of polymers; polyimides; Polymers with particular properties; Preparation, kinetics, thermodynamics, mechanism and catalysts; solubility; thermal properties; Polyimide; Electrical properties; fluorinated dianhydride; polyimides; Fluorine containing polymer; Dielectric properties; Aromatic polymer; Mechanical properties; Experimental study; Polyaddition; Functional polymer; Thermal stability; thermal properties; Optical properties; Preparation; Soluble compound; Thermostable; solubility; Water absorption
• ISSN: 0887-624X; 1099-0518
• DOI: 10.1002/pola.20252

A novel fluorinated aromatic dianhydride, 4,4′‐[2,2,2‐trifluoro‐1‐(3‐trifluoromethyl‐phenyl)ethylidene]diphthalic anhydride (TFDA) was synthesized by coupling of 3′‐trifluoromethyl‐2,2,2‐trifluoroacetophenone with o‐xylene under the catalysis of trifluoromethanesulfonic acid, followed by oxidation of KMnO4 and dehydration. A series of fluorinated aromatic polyimides derived from the novel fluorinated aromatic dianhydride TFDA with various aromatic diamines, such as p‐phenylenediamine (p‐PDA), 4,4′‐oxydianiline (ODA), 1,4‐bis(4‐aminophenoxy)benzene (p‐APB), 1,3‐bis(4‐amino‐phenoxy)benzene (m‐APB), 4‐(4‐aminophenoxy)‐3‐trifluoromethylphenylamine (3FODA) and 1,4‐bis(4‐amino‐2‐trifluoromethylphenoxy)benzene (6FAPB), were prepared by polycondensation procedure. All the fluorinated polyimides were soluble in many polar organic solvents such as NMP, DMAc, DMF, and m‐cresol, as well as some of low boiling point organic solvents such as CHCl3, THF, and acetone. Homogeneous and stable polyimide solutions with solid content as high as 35–40 wt % could be achieved, which were prepared by strong and flexible polyimide films or coatings. The polymer films have good thermal stability with the glass transition temperature of 232–322 °C, the temperature at 5% weight loss of 500–530 °C in nitrogen, and have outstanding mechanical properties with the tensile strengths of 80.5–133.2 MPa as well as elongations at breakage of 7.1–12.6%. It was also found that the polyimide films derived from TFDA and fluorinated aromatic diamines possess low dielectric constants of 2.75–3.02, a low dissipation factor in the range of 1.27–4.50 × 10−3, and low moisture absorptions <1.3%. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 4143–4152, 2004
A series of fluorinated polyimides were prepared from a novel fluorinated aromatic dianhydride 4,4′‐[2,2,2‐trifluoro‐1(3‐trifluoromethylphenyl)ethylidene]diphthalic anhydride (TFDA) and aromatic diamines, i.e., p‐phenylenediamine (p‐PDA), 4,4′‐oxydianiline (ODA), 1,4‐bis(4‐aminophenoxy)benzene (p‐APB), 1,3‐bis(4‐aminophenoxy)benzene (m‐APB), 4‐(4‐aminophenoxy)‐3‐trifluoromethylphenylamine (3FODA), and 1,4‐bis(4‐amino‐2‐trifluoromethylphenoxy)benzene (6FAPB), by polycondensation procedure. The fluorinated polyimides have good solubility both in strong polar organic solvents and low boiling point organic solvents. The polyimide films exhibited high thermal stability associated with good mechanical properties. It was also found that the polyimide films showed good dielectric properties, which markedly affected the fluorine content in the polymer backbones