Syntheses and properties of novel fluorinated polyamides based on a bis(ether-carboxylic acid) or a bis(ether amine) extended from bis(4-hydroxyphenyl)phenyl-2,2,2-trifluoroethane

Two series of novel fluorinated aromatic polyamides were prepared from 1,1-bis[4-(4-carboxyphenoxy)phenyl]-1-phenyl-2,2,2-trifluoroethane with various aromatic diamines or from 1,1-bis[4-(4-aminophenoxy)phenyl]-1-phenyl-2,2,2-trifluoroethane with various aromatic dicarboxylic acids with the phosphorylation polyamidation technique. These polyamides had inherent viscosities ranging from 0.51 to 1.54 dL/g that corresponded to weight-average and number-average molecular weights (by gel permeation chromatography) of 36,200–80,000 and 17,200–64,300, respectively. All polymers were highly soluble in aprotic polar solvents, such as N-methyl-2-pyrrolidone and N,N-dimethylacetamide, and some could even be dissolved in less-polar solvents like tetrahydrofuran. The flexible and tough films cast from the polymer solutions possessed tensile strengths of 76–94 MPa and initial moduli of 1.70–2.22 GPa. Glass-transition temperatures (Tg's) and softening temperatures of these polyamides were observed in the range of 185–268 °C by differential scanning calorimetry or thermomechanical analysis. Decomposition temperatures (Td's) for 10% weight loss all occurred above 500 °C in both nitrogen and air atmospheres. Almost all the fluorinated polyamides displayed relatively higher Tg and Td values than the corresponding nonfluorinated analogues. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 420–431, 2003