Toshiyuki Kataoka

Kanagawa University · Department of Material and Life Chemistry

Chiral silica, which acts as a nucleating agent of poly(ε-caprolactone) (PCL), was demonstrated to induce excess handedness of lamellar twist in the banded spherulites of PCL blended with poly(vinyl butyral). The d- and l-forms of silica enhanced the right- and left-handed twists, respectively. The influences of chiral silica on the twist handednes...

p>The influence of poly(butylene succinate) (PBS) crystals on the crystallinity of poly(ethylene oxide) (PEO) in PBS/PEO blends, which exhibit interpenetrating spherulites, was examined. The degree of crystallinity, ϕ , of each component was obtained by pulsed nuclear magnetic resonance (NMR). The dilution effect, order of crystallization, and chan...

Poly(ε-caprolactone) (PCL) chains grafted onto Si substrates, namely PCL brushes, exhibited diverse structures such as dendrites, branched linear crystals, and curved crystals with dendrites when they were isothermally crystallized from melts. The crystallization was possible over a wide range of temperature. The discussion on the lamellar thicknes...

A study was conducted to investigate the surface morphology of a Poly(butylene succinate) (PBS) and poly(ethylene succinate) (PES) blend, using atomic force microscopy (AFM) to obtain detailed information on the layered structures in the crystalline/crystalline system of PBS and PES. The layered structure in the phase-separated blend was discussed...

The degree of crystallinity (φ) in interpenetrating spherulites, whereby spherulites of one component continue to grow inside those of the other component, was examined for the blends of poly(ethylene succinate) (PES) and poly(ethylene oxide) (PEO) using pulsed nuclear magnetic resonance. The value of φ for PES increased with PEO blending and was s...

We discuss the enhancement in miscibility of crystalline/crystalline blends of poly(butylene succinate) and poly(ethylene succinate) (PBS/PES) by simple melt annealing, their crystallization process and the formation of characteristic phase-separated structure. The immiscible PBS/PES blends changed into miscible blends when annealed at 150 °C. Gel...

The relation between the handedness of helical twist and the S-shaped cross section of the lamellar crystals is discussed for linear polyethylene. The lamellar crystals are found to rotate so that the convex surfaces of "S" push aside the melt when they advance in the growth direction. This relation, which has not been examined sufficiently so far,...

Spherulitic morphology and growth rate of block copolymers comprised of miscible crystalline constituents, namely poly(ethylene succinate) (PES) and poly(ethylene oxide) (PEO), were investigated. The results of the copolymers were compared with those of the blends with the same composition and molecular weight. Interpenetrating spherulites, where s...

The solution, gelation, and morphological properties of monodisperse aromatic polyamide diblock copolymers consisting of poly(p-benzamide) (PpBA), poly(m-benzamide) (PmBA), and poly(N-octyl m-benzamide) (POmBA) were investigated. The block copolymers of these polymers, PpBA-block-POmBA and PmBA-block-POmBA, formed spherical micelles or amorphous ag...

Miscible blends of three crystalline polymers, namely poly(butylene succinate) (PBS), poly(ethylene succinate) (PES), and poly(oxyethylene) (POE), exhibited interpenetrating spherulites, where a spherulite of one component grows inside the spherulites of other components. PBS and PES were immiscible above the melting points, Tm, of these substances...

The effects of the lamellar growth direction, extinction rings, and spherulitic boundaries of poly(butylene succinate) (PBSU) on the spherulitic growth of poly(ethylene oxide) (PEO) were investigated in miscible blends of the two crystalline polymers. In the crystallization process from a homogeneous melt, PBSU first developed volume-filling spheru...

Spherulites of poly (butylene succinate) (PBS) continued growing inside another PBS spherulite above the melting point of poly (ethylene oxide) (PEO) in PBS/PEO blends. This phenomenon took place when the film thickness was 10-60 μm and when the distances between the centers of PBS spherulites were less than about the twice of the film thickness. N...

This manuscript describes the preparation of new slide-ring gels by using a polyrotaxane as a cross-linker.

A novel “sliding graft copolymer” (SGC), in which many linear poly-ε-caprolactone (PCL) side chains are bound to cyclodextrin rings of a polyrotaxane, was prepared by ring-opening polymerization of ε-caprolactone initiated by hydroxylgroups of the polyrotaxane. An amorphous, flexible, and sufficiently tough elastomer film was prepared by crosslinki...

Aqueous solutions of polyrotaxanes consisting of poly(ethylene glycol) and methylated alpha-cyclodextrins (alpha-CD) were studied by means of differential scanning calorimetry (DSC), dynamic light scattering, and X-ray diffraction in order to investigate the effect of the degree of methylation on thermoresponsive behavior. Polyrotaxanes with a degr...

Calcium thiocyanate [Ca(SCN)2] aqueous solutions above 40 wt % and N-methylmorpholine N-oxide (NMMO) monohydrate, which are known to dissolve cellulose, were found to be good solvents for a polyrotaxane comprising α-cyclodextrin and poly(ethylene glycol). The polyrotaxane could be dissolved up to 12 and 10 wt % in a 40 wt % Ca(SCN)2 aqueous solutio...

Liquid-liquid equillibria (LLE) of the tertiary system of hydroxypropylated polyrotaxane (HPPR)-poly(vinyl alcohol) (PVA)-solvent have been investigated by focusing on the internal structures of HPPR-PVA blend gels. The phase diagrams of the HPPR-PVA aqueous systems displayed two liquid phases at a high concentration and molecular weight of PVA. Th...

Thermoreversible gelation and microphase formation of aqueous solutions of a methylated polyrotaxane (MePR) were investigated by means of differential scanning microcalorimetry, rheometry, and X-ray diffractometry (XRD). The aqueous solutions of MePR show a lower critical solution temperature (LCST) and form an elastic gel with increasing temperatu...

The sol−gel transition and thermosensitivity of methylated polyrotaxane (Me−PR) aqueous solutions were investigated by means of small-angle neutron scattering (SANS) and dynamic light scattering (DLS). It is known that water-solubility of polyrotaxane (PR), consisting of poly(ethylene glycol) (PEG) and α-cyclodextrin (α-CD), is very low due to stac...

Polyrotaxane fiber and polyrotaxane/cellulose blend fibers were prepared by wet-spinning of the polyrotaxane or polyrotaxane/cellulose blend solution dissolved in the new solvent system, i.e. dimethylacetamide/lithium chloride (DMAc/LiCl), into methanol and a subsequent annealing. In the resultant polyrotaxane/cellulose fiber, some undissolved rodl...

Novel thermo-gelling aqueous solution systems are developed with a polyrotaxane, consisting of methylated alpha-cyclodextrin and polyethylene glycol, based on the slide-ring properties of the macrocycles along the linear chain.

The dissolution behavior of polyrotaxanes, consisting of α-cyclodextrin and poly(ethylene glycol), with different molecular weights (2000 and 35,000) was investigated. Halogen-containing ionic liquids, such as chlorides or bromides, were found to be good solvents for polyrotaxanes, regardless of their cations. Dissolution required a high temperatur...

We reviewed the fundamental aspects and applications of slide-ring materials as new polymeric materials for DDS. The slide-ring gel is one of the slide-ring materials using sliding features most effectively and has movable cross-linking junctions. As a result, it exhibited mechanical properties quite different from chemical gels, rather close to bi...

We have prepared a polyrotaxane fiber and polyrotaxane/cellulose blend fibers by dissolving the polymers in DMAc/LiCl (8%) solvent, a recently developed solvent system for polyrotaxane, followed by wet-spinning into MeOH coagulation bath and annealing at 60°C. The flexible fibers thus obtained showed birefringence, suggesting the alignment of the p...

A novel "sliding graft copolymer (SGC)", in which many linear poly-ε-caprolactone (PCL) side chains were bound to cyclodextrin rings of polyrotaxane, was prepared by ring-opening polymerization of ε-caprolactone from hydroxyl groups of the polyrotaxane. These SGCs, i.e. supramolecules possessing a number of mobile side chains, were crosslinked with...

The deformation mechanism of “slide-ring” (SR) gels was investigated with small-angle neutron scattering (SANS). The SR gels were prepared by coupling α-cyclodextrin (CD) molecules on polyrotaxane chains consisting of poly(ethylene glycol) and CD. Because of a hollow structure of CD molecules, the cross-links made of CD molecules in a figure-of-eig...

この論文は国立情報学研究所の電子図書館事業により電子化されました。 最近、物理ゲルでも化学ゲルでもない新しい種類のゲル「トポロジカルゲル」が注目を集めている。トポロジカルゲルは伸長時に極めて柔らかい初期弾性を示すことが見出されている。我々はトポロジカルゲルの特徴である「線状高分子が架橋点を自由に通り抜ける」効果(滑車効果)に着目し、化学ゲルの3chainモデルに基づく弾性理論を拡張して、トポロジカルゲルの伸張弾性理論を得た。トポロジカルゲル特有の極端に柔らかい非線形弾性を理論的に再現することに成功した。また貧溶媒中での硬い弾性は滑車効果の消失に起因することを見出した。