Іnvestigation of complex formation of cobalt (ІІ) ions with polyacrylic acid

Abstract

The process of formation of cobalt (II) ion complexes with polyacrylic acid, their influence on the size of the tangle of polyacrylic acid macromolecules and the concentration of monomer units in it have been studied. It is shown that the reaction at a temperature of 20–300 ºC forms a complex in which the cobalt ion binds two carboxyl groups of polyacrylic acid. Binding of the third carboxyl group to the complex is prevented by a sufficiently flexible polyacrylic acid chain. Increasing the temperature significantly increases the flexibility of the polyacrylic acid chain. The formation of complexes at elevated temperature proceeds in the first order by cobalt (II) ion and hydroxyl ion and by zero order – by polyacrylic acid. The change in the concentration of monomer units in the tangle of polyacrylic acid macromolecules during the formation of a complex with a cobalt (II) ion proceeds in the first order.