Coordination and morphology of metal/polyetherurethane complexes

Abstract

Based on infrared spectra, differential scanning calorimetry, and quantum chemical calculations, this study investigated the effects of the species of metal (MnCl 2, FeCl 3, CoCl 2, CuCl 2, GaCl 3), their interaction sites and binding strength on the morphologies of polyetherurethane (PU). The calculated frequency and binding energy were consistent with the experimental results, suggesting that most of the binding strength (95%) is associated with the charge transfer from the lone pairs (on the nitrogen in NH and the oxygen in CO and COC) in the PU ligand to the metal. MnCl 2, CoCl 2, and CuCl 2 are more soluble in soft segments of PU than GaCl 3 and FeCl 3 via coordination with one or two polyether ligands and can significantly raise the glass transition temperature of PU. Conversely, GaCl 3 and FeCl 3 interact more strongly with hard-segment NH of PU than MnCl 2, CoCl 2, and CuCl 2 and markedly reduce the melting temperature of PU.