Aqueous Polymerization of Divinyl Monomers Initiated by Mn(III)-Amino Acid Chelating Agents

Abstract

The polymerization kinetics of N,N'-methylenebisacrylamide initiated by the redox pairs trisacetatomanganese(III) dehydrate-ethylenediaminetetracetic acid and trisacetatomanganese(III) dehydrate - nitrilotriacetic acid in dilute sulphuric acid medium was investigated. The rate of polymerization R_p, was proportional to [MBA]^1.1, [EDTA]^0.4 and inverse dependence to [Mn(III)] for MBA-Mn(III)-EDTA system and [MBA]^1.1, [NTA]^0.7 and inverse dependence to [Mn(III)] for MBA-Mn(III)-NTA system. The rate of manganic ion disappearance R_m, was directly proportional to [Mn(III)] and [Red] but independent of monomer for both the systems. Both R_p and R_m were not affected by the changes in [H⁺], ionic strength, added Mn(II) and R_p decreased with the addition of sodium nitrate. The activation energy was evaluated by using Arrhenius plot. Suitable mechanism has been proposed to explain the observed kinetic data.