Fabrication and characterization of novel high-performance fluorinated polyimides with xanthene pendent architecture: Study of thermal, photophysical, antibacterial and heavy metal ion adsorption behavior

Two series of new fluorescent polyimides (PIs) with different functional groups such as flexible ether linkages, substituted imidazole, photoactive xanthene pendant, and electron withdrawing CF3 groups were prepared using novel monomers and three commercially available dianhydrides. The structures of two diamines and PIs were fully characterized by elemental analysis, FT-IR and H-1 NMR spectroscopy. The prepared polymers were amorphous with inherent viscosity ranged from 0.38 to 0.66 dL/g, they were readily soluble in a variety of organic solvents and tough transparent films were prepared by solution casting method. These polymers showed useful level of thermal stability having high glass transition (T-g) (235-303 degrees C) and 10% weight loss (402-498 degrees C) temperatures with more than 62% residue at 800 degrees C under N-2. They exhibited strong UV-vis absorption in solutions and in films. Photoluminescence efficiency was affected by the chemical structure of the polymers and their quantum yields ranged from 7 to 21%. The antibacterial activity of diamines and two polymers were investigated against Grain positive and Gram negative bacteria. Also, the prepared PIs were investigated for the removal of heavy metal ions such as Cr3+, Pb2+, Hg2+, Cd2+ and Co2+ from aqueous solutions at pH 7-8. (C) 2016 Elsevier B.V. All rights reserved.