Synthesis and Characterization of New Fluorinated Aromatic Polyesters Containing Trifluoromethylphenoxy Pendant Groups

A series of novel fluorinated aromatic polyesters containing trifluoromethylphenoxy pendant groups was synthesized by interfacial polycondensation of 2-(4-trifluoromethylphenoxy)terephthalyl chloride with various bisphenols in dichloromethane. The polyesters obtained in good yields had weight-average molecular weights of 70,600-29,800 g/mol, polydispersities of 1.81-2.08, and were all amorphous. All polyesters were easily soluble in organic solvents such as N,N-dimethylformamide, tetrahydrofuran, o-chlorophenol, pyridine, and dichloromethane. These fluorinated polyesters showed glass transition temperature of 133-210 degrees C, and good thermal stability with almost no weight loss up to 378 degrees C, the 10% weight loss temperature of 472-523 degrees C as well as char yield of 32-63% at 600 degrees C in nitrogen. These polyester films cast from chloroform solutions exhibited tensile strengths ranging from 102 to 126 MPa, elongation at break from 6.3% to 11.7%, and tensile moduli from 2.1 to 3.3 GPa. The resulting polyester films also displayed low dielectric constants between 2.18 and 2.49 (1 MHz), high transparency with an ultraviolet-visible absorption cut-off wavelengths in the 332-355 nm range, and excellent electric strengths (50.4-65.6 kV/mm) and volume resistivity (2.51-6.03 x 10(16) Omega cm). (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 119: 702-708, 2011