IRON(III) CHELATING RESINS .5. CROSS-LINKED COPOLYMERS OF 1-(BETA-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-(beta-acrylamidoethyl)-3-hydroxy-2-methyl-4(1H)pyridinone (AHMP) and NN-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 X 10(8)-1.4 X 10(12) 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. (C) 1994 John Wiley & Sons, Inc.