Synthesis and characterization of fluorinated poly(aryl ether)s with excellent dielectric properties

Abstract

The rapid development of high-speed communication networks has imposed more stringent requirements on the comprehensive performance of dielectric materials. In this work, a series of fluorinated poly(aryl ether)s (FPAEs) were prepared from 4,4′-dihydroxy-2,2′-bis(trifluoromethyl)biphenyl (TFBP) and different difluoride monomers through nucleophilic substitution reactions. The FPAE films had good thermal stability, with 5% weight loss temperature (T_d5) values of 514–555 °C in nitrogen and glass transition temperature (T_g) values of 178–226 °C. Furthermore, these polymer films showed excellent hydrophobicity, with water contact angles ranging from 92.4° to 98.7°, and water absorption of 0.28–0.87%. Consequently, the FPAE films showed low dielectric constants of 2.07–2.80 and low dielectric loss of 0.002–0.006 at 11 GHz and 30 °C. These outstanding properties were attributed to their high fluorine contents and twisted biphenyl structures in the polymer chains.