Effect of uranyl perchlorate on the kinetics of polymerization of acrylamide

Abstract

The effect of uranyl perchlorate on the mechanism and kinetics of the radical polymerization of acrylamide has been investigated in aqueous solution over a range of temperatures, employing 4,4′-dicyano-4,4′-azopentanoic acid as initiator. All measurements were made in the complete absence of light. With no azo-initiator present, uranyl perchlorate has been found to initiate polymerization of acrylamide, the rate of polymerization (R 0 p) observed being approximately proportional to the concentration of the uranyl salt. The overall rate of polymerization (R p) with the azo-initiator present is directly proportional both to the concentration of monomer and to the concentration of the azo-initiator. Linear termination of polymerization is indicated by the fact that (R pR 0 p) is approximately inversely proportional to the concentration of uranyl perchlorate. An electron transfer mechanism has been proposed for the termination reaction and a dimeric ion, produced by the partial hydrolysis of the uranyl salt has been suggested as the entity responsible for initiation.