Systhesis And Properties Of Highly Hydrophilic Iminodiacetic Acid Resins

Iminodiacetic acid chelating resins show high adsorption capacity for metallic ions and high adsorption selectivity for divalent metallic ions because of their "semi-EDTA" structure. So they have become the chelating resins which are produced with the largest amount and used most widely. Most of the present iminodiacetic acid chelating resins have shown slow adsorption speed and are easily polluted by organic compounds due to their hydrophobic matrix and low swelling capacity in polar solvents. In order to overcome the shortcomings of the present iminodiacetic acid chelating resins present iminodiacetic acid chelating resins, two series of highly hydrophilic iminodiacetic acid chelating resins were synthesized in this thesis.Using crosslinked polyacrylamide as the starting resins, crosslinked polyvinylamine resins were prepared through the Holinann reairangement of the polyacrylamide resins, and poly(vinyl-iminodiacetic acid) resins were synthesized via chloroacetic acidification of the polyvinylamine resins.It was concluded that the "semi-EDTA" structure existed in most of the synthesized poly(vinyl-iminodiacetic acid) resins after experimental tests and calculation. Results obtained from measurements of the swelling capacity in water and moisture content of the resins showed that the poly(vinyl-5minodiacetic acid) resins are highly hydrophilic. Adsorption and desorption property of the poly(vinyl-iminodiacetic acid) resins for copper(ll) ion and influence of outer factors on the adsorption and desorption property were investigated by dynamic adsorption and desoiption experiments. It wasrevealed that their adsorption capacity for copper(II) ion amounted to 2.95mmol/g, copper(II) ion could be fast adsorbed and uesorbecl, and copj)er(II) ion could be thoroughly desorbed from the chelating resins. Adsorption selectivity of the chelating resins for ferrous(III), copper(II) and calciuin(II) ions were tested, and the results suggested that it is the same as that of the present poly(vinyl-iminodiacetic acid) resins.Staling from crosslinked poly(glycidyl mclhacrylate) resins, the poly(3-iminodiacelie acid-2-hydroxypropyl methacrylale) chelating resins with "semi-EDTA" structure were prepared Structures of tlie chelating resins were characterized. Adsorption properties of die chelating resins for copper(II) ion in aqueous solution were investigated. The results showed that the synthesized chelating resins were a series of highly hydrophilic chelating resins with high adsorption capacity for copper(II) ion, high adsorption and desorption speed, and good mechanical strength. The adsorption capacity of one of the chelating resins amounted to 1.3 mmol/g, and the desorption percentage of copper(II) ion reached 100%.