The preparation, metal binding ability and catalytic activity of poly itaconate copolymers with pendant ethylene amine groups

Abstract

A polymeranalogous reaction in homogeneous medium was carried out to prepare poly itaconate copolymers with pendant ethylene imine groups. Three copolymers, poly- (MHpI+DHpI), poly (MBI+DBI) and poly (MMI+DMI) were prepared, characterised and their composition analysed. The acid groups in the monoesters were reacted with ethylene diamine, diethylenetriamine, triethylenetetramine or tetraethylenepentamine in the presence of dicyclohexyl car bodiimide. Two types of polymer-metal complexes, polymer chelates and pendant-type polymer-metal complexes were prepared. The complexation between the polymeric ligands and cobalt(II) chloride or copper(II) chloride was studied by visible spectroscopy. The electron microscopy study of these polymer-metal complexes shows that the size and the number of the metal ion clusters increases proportionally with the mole percentage of the metal ions. The catalytic activity of the polymer-metal complexes on the decomposition of hydrogen peroxide has been studied. Graphical and mathematical methods were used to show and compare the catalytic activity of these polymer-metal complexes. It was found that the catalyst efficiencies were in the decreasing order of: poly(MHpI+DHpI)/EN/ Co(en)2Cl] 2+ 2Cl" ^ poly(MMI+DMI)/EN/[ Co(en)2Cl] 2+ 2C1~ ^ poly(MHpI+DHpI)/TEPA/CoCl2 ^ poly(MHpI+DHpI)/TEPA/CuCl2^ poly (MMI+DMI) /TEPA/CoCl^ poly (MMI+DMI) /TEPA/CuC12. The thermal stability of these modified polymers and polymer-metal complexes confirms that degradation was a random chain scission process and that the thermal stability of the polymer-metal complexes were higher than the polymeric ligands due to crosslinking. The viscoelasticity study shows that the modulus in the rubbery region increases when the mole percentage of the pendant ethylene amine group was less than 6.3. The glass transition temperature increases and becomes broader and ill-defined as the mole percentage of pendant ethylene amine group increases due to enhanced inter molecular interactions in the system.