Original Article
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Open Access
Featured
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Editorial |
Special issue: Polymer degradation for a sustainable future
- Makoto Ouchi
- , Reika Katsumata
- & Keiji Tanaka
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Original Article |
Synthesis of heat-resistant and water/oil-repellent aromatic polyketones bearing tetrakis(nonafluorobutyl)-p-terphenylene units
Three types of aromatic polyketones bearing tetrakis(nonafluorobutyl)-pterphenylene units were successfully synthesized via nucleophilic aromatic substitution polymerization. In particular, high-molecular-weight polymers were obtained in DMAc. These polymers have water and oil repellency, good thermal stability, and excellent solubility in typical organic solvents such as MEK, THF, CHCl3, and DMAc.
- Haruki Konta
- & Katsuya Maeyama
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Original Article |
Synthesis of optically active through-space conjugated polymers consisting of planar chiral pseudo-meta-disubstituted [2.2]paracyclophane
Optically active through-space conjugated polymers were prepared from planar chiral pseudo-meta-disubstituted [2.2]paracyclophane. The corresponding optically active pseudo-meta-linked dimers were also prepared, and their optical and chiroptical properties were compared with those of the pseudo-para- and pseudo-ortho-linked dimers. Optically active pseudo-meta-linked dimers and polymers emitted intense circularly polarized luminescence with good anisotropy factors on the order of 10–3. The electrical photoconductivities of the racemic pseudo-meta- and pseudo-para-linked polymers were also evaluated. A number of properties were explained by using time-dependent density functional theory calculations.
- Hazuki Maeda
- , Ryo Inoue
- & Yasuhiro Morisaki
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Editorial |
Special issue: Fundamentals and applications of carbohydrate polymers
- Takeshi Serizawa
- , Masato Ikeda
- & Keiji Tanaka
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Original Article |
Biobased and mechanically stiff lignosulfonate/cationic-polyelectrolyte/sugar complexes with coexisting ionic and covalent crosslinks
Lignosulfonate is one of the major industrial products from wood. To utilize this compound as a moldable and strong material, we prepared a complex of lignosulfonate with cationic polyelectrolytes and reducing sugars. This complex contains two different crosslinking structures, i.e., ionic crosslinking between lignosulfonate and cationic polyelectrolytes and covalent crosslinking via the Maillard reaction of amino groups with reducing sugars. The coexisting of two different crosslinking greatly improved mechanical strength, Young’s modulus, water resistance, and adhesive strength compared with solely crosslinked complexes composed of the same ingredients.
- Kazunori Ushimaru
- , Tomotake Morita
- & Tokuma Fukuoka
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Editorial |
Special issue: CO2: capture of, utilization of, and degradation into
- Koji Nakano
- , Yu Hoshino
- & Keiji Tanaka
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Focus Review |
Chemoselective transesterification and polymer synthesis using a zincate complex
Our recent studies on the zincate complex dilithium tetra-tert-butylzincate-catalyzed transesterification and polymerization are reviewed. In the first part of this report, the ROP of ε-caprolactone catalyzed by TBZL is described. In the second part of this report, the acylation and transesterification of alcohols with vinyl acetate and carboxylic esters catalyzed by TBZL are summarized. Next, TBZL-catalyzed polycondensations of diphenyl carbonate (DPC) with diols are discussed. In the last part of this report, the transesterifications of poly(phenyl methacrylate) (PPhMA) side chains with alcohols catalyzed by TBZL are described.
- Miyuki Oshimura
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Review
| Open AccessBiodegradability of poly(3-hydroxyalkanoate) and poly(ε-caprolactone) via biological carbon cycles in marine environments
Biodegradable plastics are gaining attention as one of the solutions to marine plastic wastes, which are increasing every year. Among them, polyhydroxyalkanoate (PHA) and polycaprolactone (PCL) are known to exhibit particularly good marine biodegradability. In this review, to understand their excellent marine biodegradability, the biosynthesis of PHA and cutin, a natural analog of PCL, and the biodegradation of PHA and PCL in the carbon cycle in marine ecosystems are described.
- Miwa Suzuki
- , Yuya Tachibana
- & Ken-ichi Kasuya
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Original Article |
Enhancement of the mechanical properties of polysaccharide composite films utilizing cellulose nanofibers
Cellulose nanofibers (CNFs) were utilized as nanofillers to improve mechanical properties of polysaccharide composite films made of polyion complexes (PICs) of chondroitin sulfate C (CS) and chitosan (CHI). Nonionic CNFs were homogeneously incorporated in the PIC gels, constructed by multiple electrostatic interactions, and the resulting free-standing films. The filler effects of CNFs were observed, especially in the Young’s modulus of the films in the wet state. Results indicated that CNFs in the films formed a rigid network structure with polysaccharides, contributing the reinforcement of the film strength.
- Yusuke Yataka
- , Ayami Suzuki
- & Mineo Hashizume
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Original Article |
Investigation of interfacial adhesion of telechelic polypropylenes for carbon fiber-reinforced plastics
The interfacial adhesion between olefinic double bond- or hydroxyl-terminated telechelic polypropylenes (PPs) and carbon fibers was studied to determine the potential of the telechelic PPs as a candidate for PP matrix resin-coupling agents for carbon fiber-reinforced PP composites. The hydroxyl-terminated PP showed higher interfacial shear strength than that of commercial PP and olefinic double bond-terminated PP. The hydroxyl-terminated PP could be used as a novel coupling agent of the PP matrix.
- Ayaka Yamaguchi
- , Tamotsu Hashimoto
- & Daisuke Sasaki
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Original Article |
Synthesis of high-molecular-weight star-shaped cyclopoymers of divinyl ethers and their network membranes via controlled cationic cyclopolymerization
Controlled cationic cyclopolymerizations of divinyl ethers with cyclohexene, norbornene, norbornane, cyclic acetal, or adamantane moiety were carried out. High-molecular-weight star-shaped cyclopolymers were synthesized by the reaction of the formed living cyclopolymers with a small amount of divinyl ether crosslinking agent. Glass transition temperatures (Tg’s) of both the cyclopolymers and star-shaped cyclopolymers were as high as 145−229 oC. Methacrylate-terminated end-functionalized star-shaped cyclopolymers were synthesized by the functionalized initiator-based living cationic cyclopolymerization of divinyl ethers followed by the chain linking reactions among the formed living cyclopolymers with divinyl ether crosslinker. The obtained end-functionalized star-shaped cyclopolymers were subjected to thermal crosslinking reaction to give star-shaped cyclopolymer networks with film-forming ability.
- Takafumi Yamamoto
- , Tamotsu Hashimoto
- & Toshikazu Sakaguchi
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Original Article |
Dissolution of a transparent cross-linked polymer monolith in water by oxidative de-crosslinking
Bulk copolymerization of bis(acryloylhydrazine) with N,N-dimethylacrylamide or N,N-diethylacrylamide yielded a transparent cross-linked polymer monolith. Upon treatment with a sodium hypochlorite solution, the cross-linked monolith dissolved in water by de-crosslinking via oxidative degradation of the diacylhydrazine moiety.
- Nobuhiro Kihara
- , Kazuya Yanaze
- & Moe Kaneko
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Original Article |
In situ synthesis of easily separable Au nanoparticles catalysts based on cellulose hydrogels
We report a facile method for synthesizing Au NPs based on alkali/urea regenerated cellulose hydrogels. By controlling the precursor concentration and the reaction temperature, the size of the Au NPs can be adjusted. The Au NP/cellulose hydrogels can be used as efficient heterogeneous catalysts in the reduction of 4-nitrophenol.
- Lin Xiaobo
- , Han Xing
- & Wang Jiahao
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Original Article |
Development of recyclable carbon fiber-reinforced plastics (CFRPs) with controlled degradability and stability using acetal linkage-containing epoxy resins
Recyclable carbon fiber-reinforced plastics (CFRPs) with controlled degradability and stability were developed by using acid-degradable acetal linkage-containing epoxy resin (BA-CHDMVG). The obtained BA-CHDMVG-based CFRPs exhibited almost the same tensile and thermal properties as those of the conventional BA-based CFRPs and underwent smooth degradation through hydrolysis with the treatment of hydrochloric acid in a tetrahydrofuran (THF)/water (9/1) mixed solvent. On the other hand, in the absence of organic solvents, the BA-CHDMVG-based CFRPs have sufficient stability toward acid in the normal living environment.
- Yoshinori Kakichi
- , Ayaka Yamaguchi
- & Hirohumi Iyo
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Focus Review |
The dawn of chiral material development using saccharide-based helical polymers
The author has recently focused on exploring novel possibilities of cellulose and amylose, which exist in great abundance on earth. In this review, the author describes the functionalization of cellulose and amylose to give novel chiral functions other than that as chiral stationary phases and their use in applications, such as asymmetric organocatalysts, chiral auxiliaries and chiral fluorescent sensors. Furthermore, the application of a saccharide-containing helical polymer, which can be prepared through polymerization of a glucose-based monomer, to a circularly polarized luminescence material is also described.
- Tomoyuki Ikai
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Original Article |
Utilization of milk protein as an environmental material: accumulation of metal ions using a protein–inorganic hybrid material
A casein–inorganic hybrid material was prepared by mixing casein, one of phosphoproteins, and a silane coupling reagent. This casein–inorganic hybrid material was stable in an aqueous solution owing to the electrostatic interactions between the phosphate group in casein and the amino group in the silane coupling reagent. The hybrid materials could selectively accumulate heavy and light metal ions and did not interact with the rare-earth metal ions. In addition, the metal ion-accumulated hybrid materials could be recycled by washing with an aqueous EDTA solution or hydrochloric acid.
- Masanori Yamada
- & Mayuna Tsuruzumi
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