Abstract: The effect of β-diketone and β-triketone,such as 3-benzy1-2,4-pentanedione(BzyAcAc),benzoylacetone(BzAc),dibenzoylmethane(DBzM) and 3-benzoy1-2,4-pentanedione(BzAcAc),on polymerization of acrylamide(AAM) initiated by ceric ion was investigated.The determination of polymerization rate and overall activation energy showed that theseβ-diketones(orβ-triketone) coupled with ceric ion can form very active redox systems.The structures of free radicals resulting from these systems were monitored by radical trapping technique and ESRspectra,and the β-diketone fragments in polyacrylonitrile initiated by above mentioned systems were detected by means of FTIRspectra end group analysis.The initiating mechanisms of ceric ion/β-diketone(orβ-triketone) systems were proposed.

Key words: β-Diketone, β-Triketone, Ceric salt, Polymerization of acrylamide