Microporous polymers from superacid catalyzed polymerizations of fluoroketones with p-quaterphenyl: Synthesis, characterization, and gas sorption properties

Novel fluorinated aromatic polymers were obtained by one-pot, metal-free, superacid-catalyzed step-polymerization of trifluoromethylalkyl 1(a-b) and trifluoromethylaryl (1c) ketones with p-quaterphenyl (A). The room temperature polymerizations performed in a mixture of trifluoromethanesulfonic acid (CF3SO3H, TFSA) with methylene chloride gave polymeric particles. Thermogravimetric analysis for the particles revealed insignificant weight loss below 500 degrees C confirming their polymeric nature. Studies of solid state NMR revealed the incorporation of p-quaterphenyl in the polymer chain. The regioselectivity of polymerizations involving p-quaterphenyl and fluoroketones has been confirmed by the preparation and NMR characterization of soluble copolymers of trifluoroacetophenone (1c) with p-terphenyl/quaterphenyl mixtures. Conformational rigidity and free volume calculations confirm polymers with medium hardness and with free volumes around 0.205-0.221 cm(3)/g. Scanning electron microscopy show rough surfaces with pore sizes around 20-50 nm. The H-2, N-2 and CO2 adsorption isotherms show that these polymers may possess intrinsic microporosity making them potential molecular sieves. (C) 2016 Elsevier Ltd. All rights reserved.