Poly(arylene ether)s with trifluoromethyl groups via meta-activated nitro displacement reaction

New poly(arylene ether)s with pendent trifluoromethyl groups were synthesized from 2,2′-bis(trifluoromethyl)-4,4′-dinitro-1,1′-biphenyl with several bisphenols. The nitro leaving group activated by the trifluoromethyl group at meta position was quantitatively displaced with phenolate ions, resulting in high molecular weight polymers. The quantum mechanical calculation of the energy state suggested that the nitro displacement reaction activated by the trifluoromethyl group at meta position is an energetically favorable process. The polymers having weight average molecular weight of 42,100–95,000 g/mol and molecular weight distribution of 2.65–2.95 were obtained. The polymers were amorphous and dissolved in a wide range of organic solvents. Transparent and flexible films were obtained by solution casting. The resulting polymers are thermally stable, and Tgs of the polymers are in the range of 176–199 °C depending on their molecular structure. All of the synthesized polymers show refractive indices in the range of 1.592–1.624 with low birefringence below 0.006.