POLYURETHANES CROSS-LINKED 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 un der small and wide angles the peculiarities of the structure of networ ks have been investigated. It was found that PU crosslinked by the met al 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 t he crosslinked PU with various types of crosslinks. The structures dis covered may be considered as similar to metal catenandes. (C) 1998 Joh n Wiley & Sons, Inc.