Preparation of iminodiacetic acid‐type composite chelating material IDAA‐PGMA/SiO2 and preliminary studies on adsorption behavior of heavy metal ions and rare earth ions

Abstract

AbstractA kind of iminodiacetic acid (IDAA)‐type composite chelating materials was prepared by first graft polymerization and subsequent polymer reaction. Monomer glycidyl methacrylate (GMA) was grafted on micron‐sized silica gel particles in the manner of “graft through” in a solution polymerization system, resulting in the grafted particles poly(glycidyl methacrylate) (PGMA)/silicon dioxide (SiO2). Subsequently, the ring‐opening reaction of the epoxy groups of the grafted PGMA was carried out with IDAA as reaction reagent, resulting in the bonding of IDAA groups onto PGMA/SiO2 and obtaining the composite chelating material IDAA‐PGMA/SiO2 particles. The effects of the main factors on the graft polymerization of GMA and the bonding reaction of IDAA were examined emphatically, and the adsorption behavior of IDAA‐PGMA/SiO2 particles toward several kinds of heavy metal ions and rare earth ions was preliminarily explored. The experiments results show that: (a) to obtain the grafted particles PGMA/SiO2 with high grafting degree, in the graft polymerization step, the reaction temperature and the used amount of initiator should be controlled. The suitable temperature is 70°C and the appropriate used amount of initiator is 1.4 % of the monomer mass. Under the optimal conditions, the grafted degree of PGMA can reach 17.50 g/100 g. (b) It is feasible to introducing of IDAA groups onto PGMA/SiO2 particles via ring‐opening reaction of epoxy groups of the grafted PGMA under alkaline conditions, and the bonding rate of IDAA group can get up to 70% based on epoxy groups of the grafted PGMA. (c)The composite chelating material IDAA‐PGMA/SiO2 possesses very strong chelating adsorption ability for heavy metal ions, and especially toward Pb2+ ion, the adsorption capacity can reach 24 g/100 g. (d) The adsorption ability of IDAA‐PGMA/SiO2 for rare earth ions is weaker than that for heavy metal ions. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012