The polymerization of acrylamide initiated with ceric ion

As part of an investigation of the graft copolymerization of acrylamide onto fibrous polymers, the homopolymerization of acrylamide initiated with relatively high concentrations of ammonium cerium (IV) nitrate was studied. The resulting polyacrylamide was purified by means of fractionation with Sephadex. The polymer contains one cerium atom per molecule, probably as an end group. Paper electrophoresis showed that the cerium atom is combined chemically to the polymer molecule. The IR spectrum of the polymer did not differ from that of polyacrylamide initiated by potassium persulfate, except the bands assigned to nitrate ion. The spectrum showed no band assigned to an unsaturated end group. A novel termination mechanism of the polymerization or formation of a complex compound between polymer and cerium is expected.