EFFECT OF COPPER IONS AND COMPLEXES WITH CROWN-ESTERS ON THE MOLECULAR MOBILITY OF CROSS-LINKED SEGMENTED POLYURETHANE

Network polyurethanes cross-linked by copper(II) ions and complexes wi th dibenzo-18-crown-6 (crown-6) were synthesized and the molecular mob ility in these polymers was studied. by the method of dynamic relaxati on spectroscopy. The effects of Cu(II) ions and Cu(II)-crown-6 complex es on the glass transition in both flexible and rigid PU blocks was de termined. Using the values of storage modulus measured in the rubberli ke stare. the average molecular mass between cross-links containing Cu (II) ions and Cu(II)-crown-6 complexes was calculated, It was establis hed that some features of the viscoelastic properties of copper-contai ning polymers are caused by the appearance of the cross- links of diff erent types, found either by direct chemical bands between metal atoms and macromolecules or by the coordination bonds between copper ions a nd electron-donor centers in macrochains. The changes observed in PU c ross-linked by Cu(II)-crown-6 complexes can be related to the spatial structure: of macrocycles occurring in the cross-link sites.