Abstract: A process for producing a polyrotaxane in a high yield and at a satisfactory cost without using a large excess of a pseudopolyrotaxane and/or without using a large excess of an activated reagent. The process for polyrotaxane production comprises: an inclusion step in which a carboxylated polyethylene glycol which is a polyethylene glycol carboxylated at each end is mixed with cyclodextrin molecules to obtain a pseudopolyrotaxane which comprises cyclodextrin molecules which include the carboxylated polyethylene glycol in their cavities as if the cyclodextrin molecules are spitted with the carboxylated polyethylene glycol; and a capping step in which the pseudopolyrotaxane is reacted with capping groups having —NH2 or —OH to obtain a polyrotaxane terminated at each end by a —CO—NH-(capping group) or —CO—O-(capping group).

Abstract: It is intended to provide a crosslinked polyrotaxane formed by crosslinking polyrotaxane molecules via chemical bonds which exhibits excellent optical properties in water or in an aqueous solution of sodium chloride; a compound having this crosslinked polyrotaxane; and a process for producing the same. The above object can be achieved by a crosslinked polyrotaxane having at least two polyrotaxane molecules, wherein linear molecules are included in a skewered-like state at the opening of cyclodextrin molecules and blocking groups are provided at both ends of the linear molecules, so as to prevent the cyclodextrin molecules from leaving, and cyclodextrin molecules in at least two polyrotaxane molecules being bonded to each other via chemical bond, characterized in that hydroxyl (—OH) groups in the cyclodextrin molecules are partly substituted with non-ionic groups.

Abstract: A polyrotaxane which has enhanced solubility and is soluble in various solvents, 2) a polyrotaxane which is reversibly responsive to an external stimulus, 3) a chemically crosslinked polyrotaxane which has a high Young's modulus and a high elongation and has a high transmittance, and/or 4) a chemically crosslinked polyrotaxane which is reversibly responsive to an external stimulus; and/or a material containing any of these; and/or processes for producing these. The polyrotaxanes each comprises: a pseudo-polyrotaxane having a structure constituted of cyclic molecules and a linear molecule with which the holes of the cyclic molecules are pierced to form a clathrate; and a blocking group disposed at each end of the pseudo-polyrotaxane so as to prevent the cyclic molecules from leaving. The cyclic molecules have a functional group represented by the following formula (I) and at least one functional group selected among functional groups represented by the following formulae (II-1) to (II-6).

Abstract: An actuator includes a spirally rolled cylindrical sheet body. The sheet body is formed by attaching an electrode on each side of a dielectric elastomer layer. When a voltage is applied to the electrodes, the sheet body is contracted along the direction of its thickness, and expanded in directions perpendicular to its thickness. The actuator is actuated by applying a voltage to the electrodes and stopping the voltage application, so that the cylindrical sheet body is extended and contracted along the direction of the axis. The material forming the dielectric elastomer layer has a low strain region, where the value of a strain based on a stress acting on the dielectric elastomer layer varies from zero to a value that is greater than and close to zero, and a high strain region, where the value of the strain is greater than that in the low strain region. The Young's modulus in the low strain region is less than the Young's modulus in the high strain region.

Abstract: A process for producing a polyrotaxane in a high yield and at a satisfactory cost without using a large excess of a pseudopolyrotaxane and/or without using a large excess of an activated reagent. The process for polyrotaxane production comprises: an inclusion step in which a carboxylated polyethylene glycol which is a polyethylene glycol carboxylated at each end is mixed with cyclodextrin molecules to obtain a pseudopolyrotaxane which comprises cyclodextrin molecules which include the carboxylated polyethylene glycol in their cavities as if the cyclodextrin molecules are spitted with the carboxylated polyethylene glycol; and a capping step in which the pseudopolyrotaxane is reacted with capping groups having —NH2 or —OH to obtain a polyrotaxane terminated at each end by a —CO—NH-(capping group) or —CO—O-(capping group).

Abstract: A gel composition is provided, which in addition to being able to expect that various properties attributable to polyrotaxane will be retained, easily ensures stability, has superior shock absorbability and facilitates control of refractive index. The present invention provides a gel composition comprising a material having a network structure containing a polyrotaxane and a non-aqueous solvent, applications of the gel composition, and a process for preparing the gel composition.