Removal of chromium, copper, and nickel ions using bidentate polymeric ligand derived from 4‐aminophenol and salicylaldehyde

The monomer 5‐(4‐acryloyloxyphenylazo)salicylaldehyde [5,4‐APASAL] was prepared and polymerized in dimethylformamide (DMF) at 70°C using benzoyl peroxide as free radical initiator. Poly5‐(4‐acryloyloxyphenylazo) salicylaldehyde [poly(5,4‐APASAL)] was characterized by infrared and nuclear magnetic resonance spectroscopic technique. The molecular weight of the polymer was determined by gel permeation chromatography method. Cu(II), Ni(II), Cr(III), and Cr(VI) complexes of poly(5,4‐APASAL) were prepared. Elemental analysis of polychelates suggests that the metal to ligand ratio is about 1 : 2. The polymer metal complexes were also characterized by XRD, magnetic moment, and thermal analysis. The effect of pH and electrolyte concentration in the metal uptake behavior of the polymer was also studied.