POLYMERS
Online ISSN : 2185-9825
Print ISSN : 0454-1138
ISSN-L : 0454-1138
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  • 2024 Volume 73 Issue 7 Pages 319
    Published: 2024
    Released on J-STAGE: July 01, 2024
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    Rubbers, which have attractive properties derived from entropic elasticity, have been widely utilized all over the world for a long time. On the other hand, rubbers are often utilized with compounding agents, thus the resulting mechanism of physical properties is complex and has been still widely studied. This issue focuses on the future of such old but new rubbery materials, and introduces development trends and new approaches to meet recent various social needs, such as reducing loads on the environment, realization of sustainability, and improving functionality. We hope that this issue will help you to consider the future in which we live together with rubbery materials.
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  • Masashi OTSUKI
    2024 Volume 73 Issue 7 Pages 325-327
    Published: 2024
    Released on J-STAGE: July 01, 2024
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    In the increasingly complex landscape of sustainability management, it is crucial for manufacturing industries to establish foundational sustainability-related technologies and achieve a circular economy. This environmental shift is equally significant in the tire industry. In this article, we will introduce Bridgestone, a leading company in the tire industry, and its sustainability business concept, as well as various initiatives and technology development aimed at driving it forward.

  • Naoya AMINO
    2024 Volume 73 Issue 7 Pages 328-330
    Published: 2024
    Released on J-STAGE: July 01, 2024
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    Efforts to achieve carbon neutrality are accelerating around the world to prevent global warming. In the tire industry, many manufacturers are working to achieve carbon neutrality by 2050. As an example of tire development to achieve carbon neutrality, this paper introduces the development of technology to produce butadiene, a key chemical for synthetic rubber, from ethanol, a renewable resource, and efforts toward its social implementation. In addition, we will discuss the use of machine learning (AI) technology to efficiently promote such development. The future of AI-based rubber product development is also discussed.

  • Ryo MASHITA, Tomomi MASUI, Hiroyuki KISHIMOTO
    2024 Volume 73 Issue 7 Pages 331-333
    Published: 2024
    Released on J-STAGE: July 01, 2024
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    In order to achieve a sustainable society, we are working on research towards resource reduction and performance sustainability of tire materials at cutting-edge experimental facilities such as SPring-8. With the advancement of measurement technology in cutting-edge experimental facilities, it has become possible to acquire high-quality, large amounts of data. As a result, utilizing big data has become increasingly important in accelerating tire material development. In this article, we introduce the foundation and application of big data analysis along with the latest developments in measurement technology.

PolyMANGA
Topics and Products
  • Daisuke KASAI, Takahiro WATARI, Yoshimasa YAMAMOTO
    2024 Volume 73 Issue 7 Pages 335-336
    Published: 2024
    Released on J-STAGE: July 01, 2024
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    This research aims to develop technology for the production of protein-free natural rubber and its application in automotive and medical products. The technology to be developed in this research aims to solve environmental problems related to rubber waste and wastewater generated in the rubber production process. The process efficiently removes proteins from natural rubber latex, laying the groundwork for large-scale production. The challenge is to optimize the conditions for vulcanization of protein-free natural rubber in production, since proteins that promote vulcanization have not been present in the past. They are also investigating the biodegradation of natural rubber waste by isolating bacteria capable of degrading cis-1,4-polyisoprene. In addition, they are working on innovative wastewater treatment technologies to reduce the environmental impact of chemical emissions from rubber production. Successful development of these technologies is expected to have a positive impact on the rubber and tire industry by making a significant contribution to a sustainable carbon cycle in line with climate change targets.

  • Keisuke CHINO
    2024 Volume 73 Issue 7 Pages 337-338
    Published: 2024
    Released on J-STAGE: July 01, 2024
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    In general, since rubber has a weak interaction between molecular chains, if it is not crosslinked, it will flow and cannot withstand actual use. Covalent crosslinked rubber has high mechanical strength properties due to the strong bonding force of crosslinking, but it is difficult to reshape and recycle because of the difficulty to cleave the crosslink. Meanwhile, thermoplastic elastomers use physical interactions between molecular chains to suppress fluidity and express physical properties. Although it can be reshaped by disconnecting the physical crosslink due to heat, it lacks heat resistance. Earlier, by crosslinking with strong hydrogen bonds, we developed a thermoreversible crosslinked rubber with physical properties similar to vulcanized rubber. However, the creep resistance was not at a satisfactory level because the hydrogen bond was recombined. Therefore, we developed a multi-network elastomer that introduces three types of cross-linking: covalent bonding, and clay-plane bonding, in addition to hydrogen bonding. This elastomer showed high strength and high creep resistance while being thermoplastic.

  • Yuichi AOYAGI
    2024 Volume 73 Issue 7 Pages 339-340
    Published: 2024
    Released on J-STAGE: July 01, 2024
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    Seals have progressed in terms of both shape design and material design, and from the perspective of carbon neutrality, it is important to develop products that contribute to a sustainable society. Improving energy efficiency and reduce environmental impact contributes to minimizing the carbon footprint of products. For example, in recent years, oil seals have also been used in rotating parts such as motors for electric mobilities, but these have a higher rotational speed than engines, and the amount of heat generated increases accordingly. In particular, the smaller the diameter, the easier it is for heat to accumulate, and lowering the torque and improving heat resistance will be the key to future development. In addition, with the growing interest in new energy sources such as hydrogen and the circular economy, new functions are required for automotive rubber products other than oil seals and rubber materials used in non-automobiles, and further performance improvements are being pressed. In this report, we provide an overview and prospects for the latest technologies that support them.

  • Masaki MIURA, Masakazu KAGEOKA
    2024 Volume 73 Issue 7 Pages 341-342
    Published: 2024
    Released on J-STAGE: July 01, 2024
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    Some examples of the development in polyurethane bioplastics are reported. It is important to design the composition, soft and hard segment, for building favorable micro phase separated morphology to achieve physical properties for specific applications. Castor oil-based polyol can be used for flexible polyurethane foams. The effect of dangling chain in polyurethane network is important factor in terms of resilience. Polycaprolactone-based thermoplastic polyurethane shows same level of BOD as cellulose in extracted seawater. A further study is necessary to elucidate the degradation mechanism of hard segment as well as soft segment.

Polymer Science and I: A Personal Account
Messages: “Work and Life”
Front-Line Polymer Science
  • Chie KOJIMA
    2024 Volume 73 Issue 7 Pages 345-349
    Published: 2024
    Released on J-STAGE: July 01, 2024
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    Poly(ethylene glycol), PEG, is also called poly(ethylene oxide), which is one of the most popular biocompatible polymers. Because PEG can supress the non-specific interactions with proteins and cells, PEG-modified nanoparticles (NPs) have been widely used in drug delivery system (DDS). Because of the enhanced permeability and retention (EPR) effect observed in tumor tissues, PEGylated NPs with blood circulation properties are accumulated in tumors. Recently, many researchers have reported some immunological responses of PEG, which result in the hypersensitivity reaction of PEGylated NPs and attenuated therapeutic effects of drug-loaded PEGylated NPs. Optimizing the strucure of PEGylated NPs could reduce the immune reactions of PEG, and PEG alternatives have been studied for modification to drug carriers. It was reported that the hydration properties of a model drug carrier possibly affected the biodistribution. PEG is a classical polymer, but the properties are quite unique. Therefore, the PEG research is still ongoing.

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