Likely conformation types for urethane macrorings and their effects on polyrotaxane formation

Stuart-Briegleb models have been used to consider the possible conformations of urethane macrorings and of polyrotaxanes based on them. It is concluded that a set of conformers from the initial cyclourethanes can exist and that such rings can form ordered clumps during complexing with zinc chloride, where the styrene link can penetrate into the cavity in the macroring, and where the cyclourethane conformation has a considerable effect on the degree of crosslinking by the growing polystyrene chain. The conclusions are in good agreement with experiment.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 22, No. 4, pp. 507–511, July–August, 1986.