Polyrotaxane and polyrotaxane network: Supramolecular architectures based on the concept of dynamic covalent bond chemistry

This review article concerns with the syntheses of polyrotaxanes and polyrotaxane networks that can be constructed mainly on the basis of' the concept of dynamic covalent bond chemistry. At the beginning of the review, synthetic methods of rotaxanes are briefly summarized along with several high yielding preparations. Synthesis of poly[3]rotaxane by the reaction of homoditopic monomers utilizing the thiol-disulfide interchange reaction was discussed in detail, among polyrotaxanes possessing topological bonds For the monomer linking in the main chain. Polyrotaxane network was prepared by a similar protocol from a polyfunctional crown ether and a dumbbell-shaped homoditopic axle containing two sec-ammonium salt moieties and centrally located disulfide bond. Some characteristics of the polyrotaxane network were demonstrated, including the recyclable property as the crosslinked polymer. The meaning and applicability of the reversible crosslinking/decrosslinking system developed in the polyrotaxane network are specially emphasized for unique and potential application.