Abstrait

Preparation of chelating grafted chitin possessing amidoxime moieties and its application in removal of some heavy metals from aquatic samples

Hamada Hamada Abdel-Razik, Mohamed Ramadan Aly, Azza Mohamed Al-Asmar

Modification of chitin through graft copolymerization with diaminomaleonitrile afforded chitin grafts (DAMN-g-Chitin). Potassium persulphate (KPS) and ferrous ammonium sulphate (FAS) are combined in a redox systemand used as initiator under N2 atmosphere. Optimumconditions for grafting were as follows: monomer concentration [DAMN] = 1.4 M, [KPS] = 6 x10"2mol/L, T = 75 ºC and t = 2 h for 0.5g chitin. The imparted cyano groups of the grafted chitin polymer chains (with degree of grafting up to 234 %) were converted into amidoxime groups by the reaction with hydroxylamine hydrochloride. The complexing ability of amidoximated DAMNgraft-Chitin copolymer was investigated with respect to the adsorption of Pb2+, Cd2+, Zn2+, Fe3+, Cu2+, Ni2+ and Co2+ from aqueous solution.