Abstract: A process is provided by which a polyrotaxane including cyclic molecules having a relatively long graft chain is easily obtained. Also provided is a polyrotaxane which includes cyclic molecules having a radical polymerization initiation site and is for use as a raw material in the process. The polyrotaxane comprises: a pseudo-polyrotaxane comprising cyclic molecules clathrated with a linear molecule, the cavities of the cyclic molecules having been pierced by the linear molecule; and blocking groups disposed respectively at both ends of the pseudo-polyrotaxane so as not to release the cyclic molecules. The cyclic molecules in the polyrotaxane have a radical polymerization initiation site.

Abstract: Disclosed are a material having high flexibility and a high dielectric constant, and a method for producing same: a material having a first polyrotaxane and a second polyrotaxane, wherein the first polyrotaxane comprises first blocking groups being disposed at both ends of a first pseudo-polyrotaxane—formed from the opening of a first circular molecule being enclathrated by being skewered by a first linear chain molecule—in a manner so that the first circular molecule does not detach; the second polyrotaxane comprises second blocking groups being disposed at both ends of a second pseudo-polyrotaxane—formed from the opening of a second circular molecule being enclathrated by being skewered by a second linear chain molecule—in a manner so that the second circular molecule does not detach; said first and second polyrotaxane are formed from crosslinking with the first and second circular molecules therebetween; said material is solvent free; and the material has a dielectric constant at 1 kHz of at least 6.0.

Abstract: A material comprising crosslinked polyrotaxanes which exhibits desired viscoelasticity, particularly stress-strain characteristics with a wide low-stress region, in spite of being free from solvent; and a process for production of the same. The material comprises a first polyrotaxane bearing first cyclic molecules and a second polyrotaxane bearing second cyclic molecules, and the first and second polyrotaxanes are crosslinked via the first and second cyclic molecules. The material is free from solvent and exhibits a stress of 2.0 MPa or below at 50% strain.

Abstract: Provided are a polyrotaxane capable of using an aqueous solvent in a fabricating process although it has hydrophobicity, an aqueous composition having the polyrotaxane, a crosslinked body comprising the polyrotaxane, etc. The polyrotaxane comprises blocking groups located at both ends of a pseudo-polyrotaxane having cyclic molecules and a linear molecule which pierces the cavities of the cyclic molecules in a skewered manner to form a clathrate therewith so as not to detach the cyclic molecules, wherein the cyclic molecules have a group represented by Formula I, a group represented by Formula II and a group represented by Formula III. Incidentally, M represents, for example, a group derived from ring-opening polymerization of ?-caprolactone or the like, A represents a hydroxy group or the like, B represents a —COOH group or the like, and C represents A and/or B: -M-A??Formula I; -M-B??Formula II; and —C??Formula III.

Abstract: A process is provided by which a polyrotaxane including cyclic molecules having a relatively long graft chain is easily obtained. Also provided is a polyrotaxane which includes cyclic molecules having a radical polymerization initiation site and is for use as a raw material in the process. The polyrotaxane comprises: a pseudo-polyrotaxane comprising cyclic molecules clathrated with a linear molecule, the cavities of the cyclic molecules having been pierced by the linear molecule; and blocking groups disposed respectively at both ends of the pseudo-polyrotaxane so as not to release the cyclic molecules. The cyclic molecules in the polyrotaxane have a radical polymerization initiation site.

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.