Abstract

Radical copolymerizations of 1-vinyl-2-pyrrolidone with acrylamide and N,N?-dimethylacrylamide at different feed ratios were investigated. The copolymers were characterized by Fourier transform infrared spectroscopy, 1H NMR, and 13C NMR spectroscopy. The copolymer composition was determined from the 1H NMR spectra and found to be statistical. The metal complexation of poly(acrylamide-co-1-vinyl-2-pyrrolidone) and poly(N,N?-dimethylacrylamide-co-1-vinyl-2-pyrrolidone) for the metal ions Cu(II), Co(II), Ni(II), Cd(II), Zn(II), Pb(II), Fe(III), and Cr(III) were investigated in an aqueous phase. The liquid-phase polymer-based retention method is based on the retention of inorganic ions by soluble polymers in a membrane filtration cell and subsequent separation of low-molecular compounds from the polymer complex formed. The metal ion interaction with the hydrophilic polymers was determined as a function of the pH and the filtration factor. Poly(N,N-dimethylacrylamide-co-1-vinyl-2-pyrrolidone) showed a higher affinity for the metal ions than poly(acrylamide-co-1-vinyl-2-pyrrolidone). According to the interaction pattern obtained, Cr(III) and Cu(II) formed the most stable complexes at pH 7. Pb(II) and Zn(II) were not retained. © 1999 John Wiley & Sons, Inc.