Living radical polymerization of acrylonitrile catalyzed by copper with a high concentration of radical initiator and its application in removal of Ag(I) after modification

In this study, we reported the synthesis of polyacrylonitrile (PAN) via living radical polymerization in N, N-dimethylformamide using carbon tetrachloride as initiator, copper(II) chloride (CuCl2)/hexamethylenetetramine as catalyst system, and 2,2-azobisisobutyronitrile as a high concentration of thermal radical initiator. The polymerization proceeded in controlled/living manner as indicated by first-order kinetics of the polymerization with respect to the monomer concentration, linear increase of the molecular weight with monomer conversion and narrow polydispersity. Higher polymerization rate and narrower molecular weight distributions were observed with CuCl2 less than 50 ppm. The rate of polymerization showed a trend of increase along with temperature. The modified PAN containing amidoxime group was used for extraction of Ag(I) ions from aqueous solutions. The adsorption kinetics data indicated that the adsorption process followed pseudo-second-order rate model. The isotherm adsorption process could be described by the Freundlich isotherm model. (c) 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013