Novel poly(arylene ether)s containing multi-substituted pentaphenylene moiety

Three novel 2-trifluoromethyl-activated bisfluoro monomers have been synthesized successfully using a Suzuki-coupling reaction of 4-fluoro-3-trifluoromethyl phenyl boronic acid with 4,4′-dibromo-p-terphenyls with varied phenyl substitution on the middle phenylene ring. Three monomers were converted to a series of phenyl substituted poly(arylene ether)s by nucleophilic displacement of the fluorine atoms on the terminal benzene ring with several bisphenols. The polymers obtained by displacement of the fluorine atoms exhibit weight-average molecular weight up to 2.25×105g/mol in GPC. Thermal analysis studies indicated that these polymers did not show melting endotherms but did show ultrahigh Tg values up to 334°C in DSC and outstanding thermal stability up to 671°C for 5% weight loss in TGA under nitrogen atmosphere. The polymers are soluble in a wide range of organic solvents: THF, CHCl3, NMP, DMAc, DMF, toluene, etc., and are insoluble in DMSO and acetone at room temperature. Transparent and flexible films were easily prepared by solution casting from chloroform solution of each of the polymers. The UV absorption spectra of thin films showed no absorption in the visible light region of the spectrum, suggesting a good application to optical transparent materials in the visible light region of the spectrum.