| POLYMERS Vol.73 No.5 |
| >> Japanese | >> English |
COVER STORY
ONE for Polymer Synthesis, Properties, and Functions |
| COVER STORY: Highlight Reviews |
| Alternating Copolymers of Commodity Monomer Units: Synthesis and Sequence-Dependent Properties | Makoto OUCHI |
| <Abstract> We have designed some pendant-transformable monomers suitable for alternating radical copolymerization and selective radical cyclopolymerization to achieve a library synthesis of alternating copolymers made of commodity monomer units such as (meth)acrylate, styrene, acrylamide, and vinyl ether carrying various pendant groups. The properties/functions derived from controlled sequence were also evaluated through comparison with sequence-uncontrolled copolymers. Keywords: Sequence / Radical Copolymerization / Alternating Copolymer / Post-Polymerization Modification |
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| Polymerization of Eco-Friendly Super Engineering Plastic “XecoT” | Makoto NAKAI |
| <Abstract> “XecoT” is an eco-friendly super engineering plastic. It is crafted from plant-derived raw material 1,10-decanediamine, and exhibiting excellent performance as a heat-resistant nylon. The proprietary polymerization method was developed by fusion of nylon polymerization technology and powder technology. It has been in production and available for sale since 2012. Keywords: XecoT / 1,10-decandiamine / Unitika / Nylon / Powder |
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| Battery Materials Design Based on Heteroatom Chemistry | Noriyoshi MATSUMI |
| <Abstract> Various battery materials design utilizing hetero atom chemistry is introduced. A lithium borate type polymer binder was found to enable fast charge-discharge when employed as binder for graphite anode. When polyborosiloxane showing self-healing property was used as coating material for silicon anode, stabilized cycling bahavior was observed in comparison with the case of PVDF. Self-healing behavior of polyborosiloxane on silicon was clearly observed by SEM. Highly nitrogen doped carbon prepared by calcination of polybenzimidazole precursor was found to be an excellent anodic material for fast charge-discharge due to its expanded d-spacing and large ionic diffusion constant. Keywords: Lithium-Ion Secondary Batteries / Hetero Atom Chemistry / Polymer Binders / Solid Electrolyte Interface / Active Materials / Nitrogen-Doped Carbon / Silicon Anode / Fast Charge-Discharge |
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| COVER STORY: Topics and Products |
| Chemical Recycling of Plastics utilizing Hydrogen Gas | Takanori IWASAKI, Kohei TAKAHASHI |
| <Abstract> Chemical recycling of plastics has received much attention to realize a sustainable society through carbon neutralization. In this context, we have developed transition-metal-catalyzed hydrogenolysis of plastics into their monomers. A novel Ir complex bearing a phosphine-pyrrolido ligand catalyzed hydrogenolysis of ureas into formamides and amines. This Ir catalyst showed a unique chemoselectivity that discriminated urea even in the presence of more reactive carbonyl functionalities, including ester and amide. The Ir catalyst degraded polyurea resin into diformamide and diamine. Because dehydrogenative polymerization of diformamides and diamines has been reported, the combination of these catalyses enables chemical recycling of polyurea resin only by H2 transfer. Another important target resin to be degraded is epoxy resins, whose main chain comprises the ethereal C(sp3)–O bond. Ni-catalyzed hydrogenolysis of β-hydroxyalkyl aryl ether has been developed, which was successfully applied to a degradation of an amine-cured bisphenol A based epoxy resin with recovery of bisphenol A in good yield. Keywords: Hydrogen Gas / Hydrogenolysis / Catalyst / Chemical Recycling / Epoxy Resin / Polyurea Resin |
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| Development and Industrialization of Stereoregular Polynorbornenes | Shigetaka HAYANO, Akira FURUKO |
| <Abstract> A stereoregular Cyclo Olefin Polymer was developed as a means to enhance various properties of conventional Cyclo Olefin Polymer (COP). Stereocontrol of ROMP of norbornene monomers was achieved in the industrial scale. Thermal properties of stereoregular hydrogenated polynorbornenes were investigated thoroughly. The designed stereoregular COP, ZEONEX®T62R, has high Tg and heat-resistant yellowing. ZEONEX®T62R is being used for automotive applications including sensing cameras and sensors, taking advantage of these characteristics. We will use the Stereocontrol of ROMP technology to develop new COP in the future. Keywords: LiDAR / Cycloolefin / Metathesis / ROMP / Stereoselective / Stereoregular / Crystalline / Polyolefin |
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| Viscoelasticity of Transient Network Materials with Temporal Crosslinks | Takuya KATASHIMA |
| <Abstract> Polymer networks like rubber and gels are formed by crosslinking polymer chains into three-dimensional networks, displaying unique elasticity. Transient networks, different from rubber and gels, form through reversible bonds and exhibit gel-like behavior under stress but act like liquids over time. This article addresses challenges in understanding the viscoelastic properties of these materials. Traditional models, based on rubber elasticity and cross-link lifespan, clashed with experimental findings due to limited control over network structures. The author introduced a model transient network, using boronic acids and diols for reversible cross-linking at branched polymer ends, allowing structural control. Surface Plasmon Resonance (SPR) studies revealed that viscoelastic relaxation times are influenced by both crosslink lifetime and network structure. These findings underscore the importance of the network’s backbone in viscoelasticity understanding and open avenues for future material functionalization applications. Keywords: Polymer Networks / Transient Networks / Rheology / Viscoelasticity / Surface Plasmon Resonance |
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| High-Performance and Environmentally Friendly Plastic Production through Cinnamic Acid Derivatives | Kenji TAKADA |
| <Abstract> Bioproducible 4-aminocinnamic acid selectively produces symmetric dimers (truxillic acid/truxinic acid) by chemical treatment and photodimerization. The unique structure of these dimers allow for the synthesis of high-performance plastics such as biobased polyimides and polyamides. By tuning the functional group of cinnamic acid, diamines with a bending structure are obtained. Polyimides derived from these diamines exhibit organic solvent solubility and can repeatedly form films with sufficient strength. In addition to organic solvent solubility, alkali metal saltation of the carboxylic acid can impart water solubility to the biobased polyimide. This modification reaction not only confers water solubility, but also facilitates hydrogel formation, suggesting a reactive polyimide. The distinctive structure provided by cinnamic acid is a promising material for precise control of material properties and will promise future developments in areas such as tailor-made physical properties. Keywords: Cinnamic Acids / Biobased Polymers / [2+2]Cycloaddition Reaction / Polyimides |
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| Polymer Science and I: A Personal Account |
| Selection and Concentration of a Young Researcher | Akihiro NISHIGUCHI |
| <Abstract> “Selection and concentration” refers to the concentration of management resources in specific business fields, and is also used in science and technology policy. Here, I would like to introduce my research by applying the words “selection and concentration” to my own research life. |
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| Front-Line Polymer Science |
| Ion-Pairing Assemblies of Charged π-Electronic Systems for Nonconventional Properties and Functionalities | Yohei HAKETA, Hiromitsu MAEDA |
| <Abstract> Ion pairs of charged π-electronic systems form assemblies with ordered arrangement through iπ–iπ interactions. The assemblies show various functionalities derived from the unique arrangement of the charged π-electronic systems with fascinating structures and electronic states. We summarize recent advances and achievements of the ion-pairing assemblies especially focusing on their assembly styles. Keywords: Charged π-Electronic Systems / Ion-Pairing Assemblies / Dimension-Controlled Assemblies / iπ–iπ Interactions |
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