High optical transparency, low dielectric constant, and light color of organosoluble polyamides based on 10,10-bis[4-(4- amino-3-trifluoromethylphenoxy)phenyl]- 9(10H)-anthrone

Abstract

A new aromatic diamine, 10,10-bis[4-(4-amino-3-trifluoromethylphenoxy)phenyl]-9( 10H)-anthrone (BATFPA), has been synthesized from anthrone via three-step procedure. Low-temperature polycondensation of BATFPA with various aromatic dicarboxylic acid chlorides produced novel fluorinated polyamides with moderate to high inherent viscosities of 0.75–1.03 dL/g while the weight-average molecular weight and number-average molecular weight were in the range of 66,000–74,000 and 37,000–41,000, respectively. Nearly, all the polymers were readily soluble in polar solvents, such as N,N-dimethyl acetamide (DMAc), N-methyl-2-pyrrolidinone, pyridine, and tetrahydrofuran, and afforded transparent, light-colored, and flexible films upon casting from DMAc solvent. These polymers had glass transition temperatures of 249–309°C, 10% weight loss temperatures of 486–517°C, and char yields of 53–61% at 800°C under nitrogen. All polymers were amorphous and their films exhibited tensile strengths of 64–86 MPa, tensile moduli of 1.8–2.2 GPa, and elongation at break of 10–18%. These polymers had dielectric constants ranging from 3.25 to 3.76 (100 Hz), low moisture uptake in the range of 0.72–1.18%, and high transparency with an ultraviolet–visible absorption cutoff wavelength in the 360–378 nm range.