Synthesis of polyacrylonitrile by single-electron transfer-living radical polymerization using Fe(0) as catalyst and its adsorption properties after modification

Fe(0) was firstly used as single-electron transfer-living radical polymerization catalyst for acrylonitrile polymerization using carbon tetrachloride as initiator, hexamethylenetetramine as N-ligand, and N,N-dimethylformamide as the solvent at 65 °C. First-order kinetic studies indicated that this polymerization proceeded in a “living”/controlled manner. The living nature of the polymerization was also confirmed by chain extension of methyl methacrylate with polyacrylonitrile (PAN) as macroinitiator. Furthermore, PAN was modified with NH₂OH·HCl to generate amidoxime groups for extraction of heavy metal ions (Hg²⁺) from aqueous solutions. Fourier transformed infrared spectroscopy was performed to characterize chemical composition and structure. The adsorption property of Hg²⁺ was investigated at different pH values of aqueous solutions and distilled water. The maximal saturated adsorption capacity of Hg²⁺ was 4.8 mmol g⁻¹.