Polyurethanes crosslinked by metals and their complexes with crown ether

Two types of crosslinked polyurethanes (PU) have been synthesized: (a) PU crosslinked by metal ions (Cu²⁺ and Co²⁺), and (b) PU crosslinked by the complexes of metals with crown ether. Using X-ray scattering under small and wide angles the peculiarities of the structure of networks have been investigated. It was found that PU crosslinked by the metal crown ether complexes have a looser structure because of the bulky crosslink and diminished molecular mobility of the chains between two crosslinks, as was proven by the dielectric spectroscopy method. The X-ray and IR data have allowed proposing a scheme of the structure of the crosslinked PU with various types of crosslinks. The structures discovered may be considered as similar to metal catenandes. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1379–1386, 1998