Synthesis of polyurea rotaxanes using a cyclodextrin complex of α,ω-diamine

Polyaddition of alpha-cyclodextrin (alpha-CD) inclusion complex of ethylene glycol bis(2- aminoethyl)ether with 4,4'-methylenebis(1-isocyanatobenzene) (MDI) provided a pseudopolyrotaxane. Similar reactions of alpha-CD inclusion complex of poly(tetrahydrofuran) terminated with 3-aminopropyl groups with MDI and with 1-methyl-2,4-phenylene diisocyanate gave polyurea pseudorotaxane and polyrotaxane, respectively. The H-1 NMR spectrum indicates that molar ratios of alpha-CD to the polyurea chain in polyrotaxanes are 55, 24, and 45%, respectively. Formation of the rotaxane structure was confirmed by X-ray diffraction analysis and GPC measurement. DSC measurement indicates that they show higher glass transition temperature than that of the corresponding CD free polymers.