Takeshi Kakibe

University of Hyogo

Engineering plastics and their composites are utilized in mechanical and civil engineering structures. It is very important to understand the fatigue crack growth mechanism of polymeric materials for structures from the viewpoint of long-term reliability. The aim of this study is to investigate fatigue crack growth properties and the fracture tough...

In this study, we describe the synthesis of a cholesterol-linked cyanostilobazole salt dye and the tuning of its luminescence by physical stimuli such as electricity and grinding. The dyes exhibited liquid-crystalline properties at temperatures above 170 °C. Some of the solutions were transformed into orange luminescent gels upon the addition of po...

To clarify the electronic structures and obtain the association structures of ionic liquids (ILs), X-ray absorption near-edge structure (XANES) spectra in the C K, N K, O K, and F K regions of a systematic series of ILs were measured. The C K-XANES spectra were theoretically analyzed using density functional theory (DFT) calculations. Focusing on t...

From the viewpoint of environmental protection and sustainability, developing green synthetic processing methods for cellulose derivatives, the most abundant biomass on Earth, is crucial. In this study, allyl cellulose was synthesized under homogeneous conditions. Cellulose was first dissolved in a tetrabutylphosphonium hydroxide aqueous solution,...

The cover image created by Hajime Kishi and his colleagues shows the energy absorption characteristics (calculated loss factor) of laminates, which consisted of block copolymer/tackifier blends and cured epoxy substrates. They were determined using the RUK equation including the viscoelastic parameters (both tan δ and storage modulus) for the blend...

The γ‐ray resistance of epoxy network polymers was evaluated. Bisphenol A diglycidyl ether (DGEBA) was used as an epoxy oligomer, and 4,4′‐diaminodiphenylmethane (DDM), hexahydrophthalic anhydride (HHPA), and phenolic novolac (PN) were used as curing agents. The thermally crosslinked polymers were irradiated with 0–10 MGy of γ‐rays. The crosslink d...

This work studied the effects of tackifiers on the impact energy absorption properties of block copolymers (BCPs) comprising poly(styrene)‐b‐poly(isoprene)‐b‐poly(styrene) (SIS) and poly(methyl methacrylate)‐b‐poly(n‐butyl acrylate)‐b‐poly(methyl methacrylate) (MAM). A rosin ester resin (RE) and an aliphatic petroleum resin (C5PR) were compared as...

Room temperature ionic liquids (ILs) are the appealing research target as electrolytes for lithium batteries. The cation and anion structure of ILs influences their physical and chemical properties. In this study, an electron-donating branched substituent was introduced into imidazolium cations to promote charge delocalization and to improve the re...

The structure formation and electrical conductivity of poly[diglycidyl ethers of bisphenol-F (DGEBF)]/poly[dicyclopentenyloxyethyl methacrylate (DPOMA)]/silver (Ag) filler composites were investigated. DGEBF/40 wt% DPOMA blends showed low viscosity and formed co-continuous phase structures at the micrometer scale via in situ radical polymerization...

Methacrylic copolymers have high potential as matrix polymers for carbon fiber reinforced thermoplastics (CFRTPs) due to their superior mechanical properties and the versatility of the monomers. However, the methacrylic copolymers have low solvent resistance, compared to epoxy, polyamide, and polypropylene, due to their un-cross-linked amorphous st...

The thermal conductivity of the diglycidyl ethers of bisphenol-A (DGEBA)/4,4’-diaminodiphenylmethane (DDM)/polyethersulphone (PES)/silver (Ag) filler composites has been investigated. The DGEBA/DDM/PES blend as the matrix for the polymer composites formed co-continuous phase structures at the micrometer scale via reaction-induced phase separation d...

Room-temperature ionic liquids (ILs), low-temperature molten salts, are regarded as green solvents and have been widely investigated concerning their many unique properties, particularly extremely low vapor pressure. However, it is difficult to purify ILs by distillation because of their low vapor pressure. The purity of ILs influences their proper...

A review on the use of “task-specific” ionic liquids for designing of the structures of ions. Ionic liquids （ILs）entirely consist of ions. In recent years, functionalized ILs, called “task-specific” ILs （TSILs）, are finding anincreasing number of applications in synthesis, separation, catalysis, and electrochemistry.

We examined the effect of high pressure on the sol–gel phase transition of a resorcinol–formaldehyde (RF) aqueous solution to a RF hydrogel, which was hold under a certain pressure varied in the range from the ambient pressure to 400 MPa. By employing the dynamic light scattering method, we analyzed the scattered intensity of a He–Ne laser which wa...

Carbon black (CB) particles were employed as a reinforcing filler in carboxyl‐terminated butadiene acrylonitrile rubber (CTBN)/epoxy resin (diglycidyl ether of bisphenol‐A (DGEBA))/aromatic diamine (diamino diphenyl methane (DDM)) network polymer blends. The strength, modulus, and ability to absorb impact energy of the resulting composites were eva...

A series of solid state network polymer electrolytes comprising segments of poly(ethylene glycol) diglycidylether (PEGDGE) and diglycidyl ethers of bisphenol-A were prepared to explore the relationships betweentheir structure and ionic conductivity. The mobility of several polymer components, including curing agents,were observed using nuclear magn...

Etherification of cellulose was performed using a mixture of ionic liquids (ILs) playing roles in both cellulose dissolution and catalysis. We investigated the effects of the reaction time and the ratio of these ILs in the mixture. Cellulose etherification was performed in these IL mixtures. The proportion of propoxy cellulose exceeded 2.5 after 24...

Etherification of cellulose, in particular, its epoxidation in the presence of glycidol, was conducted using a binary ionic liquid mixture as the solvent and catalyst. The influence of reaction time and component ratio was studied. The degree of cellulose epoxidation exceeded 2.2 at 60 °C for 18 h.

Solid state polymer electrolytes based on the nanostructured block copolymers including the conventional ionic liquid which have different alkyl chains were prepared. The site selectivity of ionicliquids in the nanostructured polymer matrix has been investigated by thermal properties and ionicconductivity. The glass transition temperatures of polym...

A binary ionic liquid (IL) system based on a common organic cation, N,N-diethyl-N-methyl-N-(2-methoxyethyl)anmmonium (DEME+), with mixed anion of bis(trifluoromethanesulfonyl)imide (TFSI−) and bis(fluorosulfonyl)imide (FSI−) has been examined as a supporting electrolyte of rechargeable magnesium batteries. Basic properties of the mixed IL were meas...

A series of imidazolium cation-based ionic liquids (ILs) have been synthesized and examined as ionic solvents for rechargeable magnesium batteries. The electrolyte solutions consist of these ILs dissolving methylmagnesium bromide with tetrahydrofuran (MeMgBr/THF). The chemical structure of imidazolium cation much influenced the ionic conductivity a...

We study the electrochromic response of N,N′-diheptyl-4,4′-bipyridinium dibromide (heptyl viologen, HV) incorporated mono-molecularly into DNA minor grooves. DNA in which Na+ cations have been substituted by 1-dodecyl-3-methylimidazolium (C12MIDNA) was prepared and cast as a thin film on an ITO glass electrode. HV was then introduced into the DNA f...

Two different viologens have been incorporated into double-strand DNA on ITO glass electrodes. Thus prepared DNA/viologen complex film showed reversible two-step color change by potential control.

Viologens, mono-molecularly immobilized in DNA grooves, show reversible colour changes without attenuation during potential switching after covering with ionic liquid type polymers.