Adsorption and desorption of phosphate and nitrate ions using quaternary (polypropylene-g-N,N-dimethylamino ethylmethacrylate) graft copolymer

Study has been made on the preparation of functionalized copolymer by grafting N,N(dimethylaminoethyl) methacrylate (DMAEMA) onto polypropylene (PP) films using gamma-irradiation technique. The effect of monomer concentration and irradiation dose on the grafting yield was studied. It was found that grafting yield increases with increasing the monomer concentration and irradiation dose. Subsequent quaternization of the amine group of PDMAEMA graft chain using different reagents, 1-bromo octadecane, methyl iodide and benzyl chloride, to improve their ionic character was carried out. The grafted PP films were characterized by IR spectroscopy, and mechanical and thermal properties. During the adsorption of phosphate (PO43-) and nitrate (NO3-) ions, the rate of adsorption, pH effect, desorbability and initial feed concentration effect were investigated. It was found that the adsorption Of PO43- and NO3- ions increases with increasing the adsorption time up to 10h and decreases with increasing the pH of medium. The desorbability is ranging from 18 to 30%, and it is relatively difficult to desorb PO43- and NO3- ions from the functionalized grafted copolymers. Results showed good possibility for the use of such functionalized grafted film in the field of removal of some anions such as PO43- and NO3- from their media. (C) 2008 Elsevier B.V. All rights reserved.