Abstract: Water-soluble polyacrylamide samples of various molecular weight, containing salicylaldehyde and lysine moieties, were prepared by copolymerization of (N-5-methacryloylamino-salicylidene-N-methacryloyl-(S)-lysinato) (pyridine)copper (II) (1) with acrylamide, followed by destruction of the copper complex by the disodium salt of EDTA. It is shown that at pH > 6 the formation of internal aldimine occurs in these samples. The degree of assembly of internal Schiff base is considerably higher than in the model low-molecular weight system and does not depend on: a) the molecular weight of the polyacrylamide sample; b) the polymer concentration in buffer solution; c) the presence of a cross-linking agent. On the basis of these data a conclusion is made that in the copolymerization of 1 with acrylamide, methacryloyl moieties, bonded with the amino groups of salicylaldehyde and lysine, form macrocycles, the cyclocopolymerization rate being much higher than the rate of cross-linked polymer formation. After the removal of copper ions from the polymer the lysine and salicylaldehyde moieties remain attached to the same polymer chain in the immediate vicinity of each other, thus favouring the formation of internal aldimine

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