Investigation on the interactions between polyurethane and metal chloride

The aim of this article is to investigate the effect of interactions between metal ions and polyurethanes(PU) on the properties of polyurethanes. In this report, interaction between metal ions(Y3+, La3+, Ca2+, Cu2+, and Li+) and polyurethanes was investigated by FT-IR spectroscopy, rheological method and TEM technique. Compared with the pure PU, obvious variation of carbonyl group vibration can be observed from the IR spectra of PU-YCl3, PU-CuCl2 and PU-LiCl composites, which indicated that there were interactions between these metal ions and the polar carbonyl groups of PU. Although the IR spectra of PU-CaCl2 systems showed little changes, the difference of rheological behavior between PU-CaCl2-DMF solution system and pure PU solution implied that the aggregation state of PU changed in the presence of Ca2+ ions, which provided the evidence that interactions between metal ions and the molecular chains of PU occurred in the solution, and similar behavior can be observed in PU-YCl3, PU-CuCl2 and PU-LiCl solution systems, respectively. TEM of PU-LaCl3 results revealed that PU possesses the ability to coordinate with metal ions, resulting in the formation of the ion clusters and phase separation in the PU-metal ion systems. In summary, there are interactions between metal ions and the carbonyl groups of PU in solid state and in DMF solution, which may provide a new way to modify the properties of polyurethanes.