高分子　Vol.73　No.1　2024年1月

高分子　Vol.73　No.1

特集　最新精密架橋高分子

展望　COVER STORY: Highlight Reviews

フェノール樹脂の架橋不均一性解明に関する研究
Elucidation of Crosslink Inhomogeneity of Phenolic Resins

首藤　靖幸・和泉　篤士
Yasuyuki SHUDO, Atsushi IZUMI

＜要旨＞フェノール樹脂の架橋不均一性を解明するため、X線・中性子散乱法を用いてゲル化直後の膨潤ゲルおよび反応後期の硬化物の構造解析を行った。また中性子準弾性散乱法を用いた樹脂硬化物中の溶媒拡散挙動の解析や、中性子反射率法を用いたフェノール樹脂／シリカ界面における不均一なナノ構造の解析例についても紹介する。
Keywords: Phenolic Resins / Thermosetting Polymers / Small-Angle X-Ray Scattering / Small-Angle Neutron Scattering / Quasi-Elastic Neutron Scattering / Neutron Reflectometry

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無機ナノシート液晶を複合化した架橋高分子
Network Polymers Composited with Liquid Crystalline Nanosheets

宮元　展義
Nobuyoshi MIYAMOTO

＜要旨＞溶媒に分散した無機ナノシートは、精密制御可能な階層的な超構造をもつ「ナノシート液晶」を形成する。本稿では、ナノシート液晶を導入したゲルやエラストマーなどの架橋高分子をご紹介する。これらは、異方的な光学特性、力学応答構造色、異方的な力学物性などを示す興味深い複合系である。
Keywords: Nanosheet / Liquid Crystal / Gel / Elastomer / Structural Color / Anisotropy

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均一ゲルが生み出したゲル研究の新潮流
New Stream in Gel Science Driven by Tetra Gel

酒井　崇匡・LI Xiang
Takamasa SAKAI, Xiang LI

＜要旨＞ゲルが、不均一な三次元の網目構造をもつ物質であることは、長く常識とされてきた。筆者らは、この常識を覆すことを目指し、テトラゲルに関する研究を行ってきた。本稿では、均一なゲルに関連すると思われるトピックスをいくつか紹介し、均一なゲルが拓く新しいゲル研究について展望する。
Keywords: Tetra Gel / Ideal Network / Non-Ergordicity / Network Disassembly Spectrometry / Expansion Microscopy / Dynamic Light Scattering

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トピックス　COVER STORY: Topics and Products

イオン液体中の超高分子量ポリマーの絡み合いによって形成される自己修復ゲル材料
Self-Healable Ion Gels from Physical Entanglements of Ultrahigh–Molecular Weight Polymers

玉手　亮多
Ryota TAMATE

＜要旨＞ Highly stretchable and self-healing polymer gels formed solely by physical entanglements of ultrahigh–molecular weight (UHMW) polymers are fabricated through a facile one-step process. Radical polymerization of vinyl monomers in ionic liquids under very low initiator concentration conditions produces UHMW polymers of more than 10⁶ g/mol with high monomer conversion, resulting in the formation of physically entangled polymer gels. The UHMW gels show excellent properties, such as high stretchability, high ionic conductivity, and recyclability. Furthermore, the UHMW gel exhibits room temperature self-healing ability without any external stimuli. The tensile experiments and molecular dynamics simulations indicate that the nonequilibrium state of the fractured surfaces and microscopic interactions between the polymer chains and solvents play a vital role in the self-healing ability. This study provides a physical approach for fabricating stretchable and self-healing polymer gels based on UHMW polymers.
Keywords: Self-Healing / Ultrahigh Molecular Weight / Ionic Liquids / Ion Gels / Physical Entanglements / Stretchable

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合成弱者の戦略～生体軟組織をそのまま使った精密材料創製
Use of Biological Tissues toward Precise Synthesis of Soft Materials

中島　祐
Tasuku NAKAJIMA

＜要旨＞　Biological tissues have a precise and hierarchical internal structure, which plays an essential role in their excellent properties and functions. In order to create synthetic materials with such biotissue-like properties, it is necessary to construct a precise internal structure inside them. While outstanding chemists are tackling this issue with their precise synthesis techniques, we, beginners of synthetic chemistry, do not have such chemical techniques. Instead of using precise chemistry, we adopt the other way to construct precise materials; that is, using existing biological tissues with precise internal structure that act as substrates of biological/synthetic hybrid materials. As an example, here I report the squid/polyacrylamide hybrid hydrogels with excellent fracture toughness. Squid mantles have well-oriented circle muscle fibers. We synthesized the polyacrylamide network in the squid mantle to create the hybrid hydrogels. Such the hybrid hydrogels exhibit excellent fracture toughness owing to the oriented muscle fibers of the squid inside them.
Keywords: Biological Tissues / Composite / Hybrid / Hydrogel / Anisotropy / Toughness / Squid / Cuttlefish

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ナノドメイン設計に基づく高分子ヒドロゲルの機能化
Funtional Hydrogels Based on Design of Nanodomain Structure

伊田　翔平
Shohei IDA

＜要旨＞　Elaborate design and precise construction of network structures is required for the development of novel hydrogel materials. We are focusing on the design of a stimuli-responsive nanodomain structure in a hydrogel using living radical polymerization techniques. For example, a dispersed and crosslinked nanodomain consisting of thermoresponsive poly(N-isopropylacrylamide) (PNIPAAm) was incorporated into a hydrogel through reversible addition-fragmentation chain transfer (RAFT) polymerization. The product hydrogels exhibited thermoresponsive mechanical toughening maintaining their original volume and transparency due to the swelling/shrinking of the nanodomains. The consistent transparency at a high temperature was observed even with as high as 50％ of thermoresponsive content. This feature allowed us to hybridize functional molecules with such hydrogels to realize the multifunctional properties in response to one stimulus. Incorporation of fluorescent carbon dots led to a simultaneous mechanical toughening and change in photoluminescence. Furthermore, the functionalization with an iridium complex afforded a hydrogel showing molecular sensing with a drastic color change and catalytic activity in N-alkylation reaction.
Keywords: Hydrogels / Living Radical Polymerization / RAFT Polymerization / Nanodomains / Mechanical Properties / Themoresponsive Properties / Carbon Dots / Iridium Complex

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グローイングポリマー　Polymer Science and I: A Personal Account

「スイッチ・ポン」の向こう側
Beyond “Switch ON”

守島　健
Ken MORISHIMA

＜要旨＞ I have studied the structure and physical properties of various soft matters, and I am currently working on biomacromolecules. I would like to make new discoveries through mastering the professionalism of measurements.

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高分子科学最近の進歩　Front-Line Polymer Science

シルセスキオキサンの精密制御合成
Precisely Controlled Synthesis of Silsesquioxanes

金子　芳郎
Yoshiro KANEKO

＜要旨＞ In this topic, I would like to focus on the fundamental structural control methods of silsesquioxanes (SQ), particularly polyhedral oligomeric SQ (POSS), because SQ has shown expanding applications in various fields. Specifically, I will discuss the size-controlled synthesis of POSS and explore the effects of the type of reaction solvent and reaction temperature/time on POSS size. Furthermore, I will explain the synthesis of large-sized POSS, including 18-mer POSS and macrocyclic ladder-like SQ. Additionally, I will present the syntheses of POSS with controlled arrangement of different side-chain groups, including POSS with a bifacial structure and para- and ortho-substituted POSS.
Keywords: Silsesquioxane / POSS / Organic-Inorganic Hybrid / Precisely Controlled Synthesis

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