Synthesis of Poly(naphthylene ether) Containing Tetraphenylmethane Group with a Low Dielectric Constant

A novel thermally stable and low dielectric poly[4,4′-bis(1-naphthyloxy)tetraphenylmethane] (2) has been successfully prepared. 4,4′-Bis(1-naphthyloxy)tetraphenylmethane (1) as a monomer was synthesized by the Ullmann reaction from 4,4′-dihydroxytetraphenylmethane and 1-bromonaphthalene. The oxidative coupling polymerization of 1 was conducted in 1,1,2,2-tetrachloroethane with iron (III) chloride as an oxidant to afford polymer 2 with number-average molecular weights up to 19,000. The 5% weight loss and glass transition temperatures of 2 were 534 °C and 258 °C, respectively. The dielectric constants (ε) of polymer 2 estimated from the refractive index and the capacitance were 2.69 and 2.75, respectively.