Iron(III) chelating resins. V. Cross-linked copolymers of 1-(B-acrylamidoethyl)-3-hydroxy-2-methyl-4(1H) pyridinone (AHMP) and N,N-dimethylacrylamide (DMAA) for iron(III) chelation studies

Iron (III) chelating resins containing 3-hydroxy-2-methyl-4(1H)pyridinone (HMP) groups were prepared from 1-(β-acrylamidoethyl)-3-hydroxy-2-methyl-4(1H)pyridinone (AHMP) and N,N-dimethylacrylamide (DMAA), using N,N-ethylene-bis-acrylamide (EBAA) as a cross-linking agent. The cross-linked AHMP-DMAA copolymer resins were very stable and exhibited a high hydrophilicity with water contents of the swollen resins of 85-90%. The iron (III) chelating capacity of the resins was determined at physiological pH, and the chelating efficiency was, in general, higher than 90%. The iron (III) chelation was about 80% after 2 h and almost complete in 8 h. The distribution ratio of iron (III) between the resin and iron (III) solutions was quite high (3700-25,000 mL/g) and depended on the initial iron (III) concentration. It was possible to remove iron completely from aqueous solutions by using excess amounts of the resin. The resin also showed a very high selectivity for iron (III), and selectivity coefficients for iron (III) in the range of 9.6 × 108-1.4 × 1012 were determined at pH 5.6 in binary solutions of Fe3+ with Mg2+, Cu2+, Ca2+, Mn2+, and Zn2+. The iron (III) chelating resins could be easily regenerated and used again without any considerable loss of their iron (III) chelating capacities