Vinyl polymerization by a cobalt complex

The rate of decomposition of the complex, sodium bis(diethanolamine)cobaltate octahydrate was studied at pH 7 and pH 1,6, respectively. This complex was found to initiate the vinyl polymerization (polymerization of acrylamide and methacrylamide) at pH 1,6 in aqueous medium. There was no polymerization at pH > 4. The dependences of the rate of polymerization on monomer concentration, initiator concentration, temperature, and pH were studied. The overall activation energy of the polymerization reaction was calculated. A kinetic reaction scheme is proposed on the basis of the experimental data.