Complex Formation between Cyclic Urethane and Zinc Chloride: Its Effect on Polyrotaxane Synthesis

Abstract The complex formation between cyclic urethane based on diethylene glycol and hexamethylene diisocyanate and ZnCl2 has been investigated by the NMR method. It has been established that coordination proceeds only through oxygen atoms of cyclic urethane. Its ability to aggregate into ordered clusterlike complexes under the influence of ZnCl2 has been proved, The effect of clusterlike complexes on styrene polymerization in the presence of such complexes and pure cyclourethane, leading to polyrotaxane formation, has also been investigated. X-ray diffractograms of extracted reaction products show the maxima typical for both polystyrene and cyclic urethane. The analogous investigation of products obtained in the presence of the linear analogue of cyclic urethane and its complexes with ZnCl2 prove that polystyrene and urethane are not chemically bonded. The number of cyclic molecules corresponding to one polymer chain in the polyrotaxanes obtained has been calculated. It was established that this number ...