Synthesis and gas transport properties of new aromatic 3F polymers

New aromatic 3F polymers were obtained from condensations of 2,2,2-trifluoroacetophenone (1) with biphenyl (a), terphenyl (b), a mixture of biphenyl with terphenyl (ab), phenyl ether (c) and diphenoxybenzophenone (d). The reactions were performed at room temperature in the Brønsted superacid trifluoromethanesulfonic acid (TFSA) and in a mixture of TFSA with dichloromethane. The polymers show high glass transition temperatures >170 °C, excellent thermal stability (decomposition temperatures ≥475 °C) and good solubility in chlorinated solvents and strong acids. The 3F polymer structures based on biphenyl and terphenyl show attractive permeability coefficients for CO2 (∼200 Barrers) and H2 (∼120 Barrers), whereas the 3F polymers that contain ether linkages have permeability coefficients in the typical range of regular polysulfone and polycarbonate. However, in sharp contrast to polysulfone and polycarbonate families, new 3F polymers possess high chemical stability and they have advantages since their reactions, based on commercially available monomers, can be carried out in one-pot at room temperature and offer a large variety of structures not possible to prepare by other synthetic methods.