Triphenylamine-containing microporous organic copolymers for hydrocarbons/water separation

Abstract

Two novel porous copolymers PBP-N-25 and PBP-N-50 were synthesized from triphenylamine and 4,4′-bis(chloromethyl)biphenyl using a combination of oxidative polymerization and Friedel–Crafts alkylation process promoted by anhydrous FeCl₃. The polymers were predominantly microporous, with apparent BET surface areas of 1362 m² g⁻¹ for PBP-N-25 and 1338 m² g⁻¹ for PBP-N-50. PBP-N-25 and PBP-N-50 possessed benzene vapor uptakes of 94.1 wt% and 107.3 wt% and cyclohexane vapor uptakes of 95.3 wt% and 83.8 wt%, while the water vapor uptakes were only 1.7 wt% and 1.2 wt%, respectively. The large amount of phenyl and methylene linkers resulted in the polymers' hydrophobicity and affinity toward aromatic and aliphatic compounds. The benzene/water vapor selectivities of PBP-N-25 and PBP-N-50 were as high as 53.5 and 63.6. Monolithic polymer M-PBP-N-25 with an apparent BET surface area of 551 m² g⁻¹ was prepared, which exhibited a good performance for oil/water separation. Owing to its hydrophobic nature and low density, the monolith was floating on the surface of water before and after collecting all of the oil from water. After removing the monolith from the surface, oil and water separated instantly.