Synthesis, characterization and heavy metal ion adsorption behavior of imidazole-based novel polyamides and poly imides

Imidazole-based polyamides (PA)s and polyimides (PI)s were prepared from condensation of a new aromatic heterocyclic diamine, 4,4>(4,4>-(2-(4-(triflouromethyl)phenyl)-1H-imidazole-4,5-dyl)bis(4,1-phenylen))bis(oxy)bis(3-(4,5-diphenyl-1H-imidazole-2-yl)aniline), with various diacids and dianhydrides, respectively. The structure of diamine, PAs and PIs were fully characterized by using elemental analysis, FT-IR, ¹H NMR and ¹³C NMR techniques. Also, adsorption capability of these polymers for removal of heavy metal ions such as Co²⁺, Cr³⁺, Cd²⁺, Hg²⁺ and Pb²⁺ from aqueous solutions was also tested at pH 7-8. The PAs and PIs showed good solubility in aprotic polar organic solvents with high thermal stability exhibiting the glass transition temperatures (T_g)s and 10% weight loss temperatures (T₁₀%) in the range of 220-286 and 383-435 degrees centigrade for PAs and 251-307 and 407-512 degrees centigrade for PIs. (author)