Preparation and Characterization of Polyesterurethane Metallopolymers Containing Transition Metal Ions

Several series of metallopolymers (MP) were synthesized from a MDI-based polyesterurethane and various transition metal ion species, namely, copper(II), manganese(II), cobalt(II), iron(III) and chromium(III). Each series of MP were prepared by using different initial molar ratios urethane groups/metal ions (U/M). MP were characterized in comparison with the parent polyurethane (PU) by atomic absorption spectrometry (AAS), UV-vis absorption spectroscopy, FT-IR spectroscopy, differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), thermogravimetric analysis (TGA) and tensile testing. The transition metal ions form coordination complexes with polyurethane functional groups, the intermolecular complexation resulting in the crosslinking of polymer chains. As a consequence, modifications take place in the original structure of PU, e.g. hydrogen bonding and crystallinity of the hard-segment domains. VIP compared with PU present differences in viscoelastic and mechanical behaviors, which generally indicate the reinforcing effect of metal ions on the polyurethane matrix, as well in thermal stability. it was revealed that each transition metal ion has specific effects on the structure and properties of PU. The implications and mechanisms behind these observations are discussed.