**1. Introduction**

50 Polyurethane

pp.(612–617)

Davletbaeva I. M., Pyataev A. V., Kalachev K. E., Sadykov E. K. & Manapov R. A. (2006) Mössbauer study of structurally ordered iron coordination compounds and polyurethanes crosslinked by them. *Polymer Science,* Ser. A, 2006, Vol. 48, No. 6,

> The formation of the polyurethanes (PU) with immobilized *in situ* co-ordinating metal compounds allows obtain structurally homogeneous systems with uniform dispersed nanosize metal containing sites. Aggregation of these metal chelate compounds is prevented due to complexing with polar groups of the polymer matrix.

> At the same time due to complex formation between the metal compound and polymer functional groups, the structuring of the forming matrix occurs on a nanoscale level. As a result, in the presence of small amounts of metal chelate compound (0,5-5%wt) both change of the polyurethane structure and properties can be observed. To understand the nature of above phenomena the influence of the weak interactions «macromolecule - metal» were analyzed on the metal-containing PUs structure, molecular dynamics and properties.

> The present study investigates the formation of nanostructured linear and cross-linked polyurethanes (LPUs and CPUs, respectively) with immobilized *in situ* mono- and polyheteronuclear chelate compounds of rare-earth and transition metals. Influence of PU topology on self organization processes in polymer matrix and its properties is also subject of analysis.
