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Updated: May 19, 2026
08:12
Depolymerizable Olefinic Polymers Based on Fused-Ring Cyclooctene Monomers
Published on: December 16, 2022
オレフィンメタテシスは,強力な炭素-炭素二重結合のダイナミックな交換を通じて,効果的なポリマーヒーリングのためのものです
1Department of Chemistry, University of California, Irvine, California 92697, USA.
Journal of the American Chemical Society
|August 8, 2012
まとめ
この研究は,移行金属触媒化されたオレフィンメタテーシスが,炭素-炭素二重結合のダイナミックな交換によって,ポリマーを効果的に治すことを示しています. ルテニウム触媒は,低温でもポリブタジーンネットワークで自己治癒を可能にします.
科学分野:
- ポリマー化学のポリマー化学について
- マテリアルサイエンス 材料科学
- カタリシス カタリシス カタリシス
背景:
- ポリマーネットワークには,多くの場合,効率的な自己治癒メカニズムが欠けている.
- ダイナミック・コヴァレンント・ボンドは,可逆的な物質特性への経路を提供する.
- オレフィンメタテシスは,C=C結合操作のための強力なツールです.
研究 の 目的:
- ポリマーの自己治癒のための移行金属触媒化されたオレフィンメタテシスを実証する.
- ポリブタジアン (PBD) ネットワークにおけるグラブス触媒の有効性を調査する.
- 様々な条件と触媒濃度の下で治癒を探求する.
主な方法:
- Grubbsの第2世代ルテニウム触媒をクロスリンクされたPBDに組み込みました.
- 治癒効率を評価するために,機械的な試験と顕微鏡分析を行います.
- 触媒の負荷,圧力,温度を体系的に変化させる.
主要な成果:
- ルテニウムで触媒化されたPBDは,ダイナミックなC=C結合交換を通じて有意な自己治癒を示す.
- 触媒のないPBDは,同一の条件下で最小限の治癒を示しています.
- サブ環境温度で効果的治癒が達成され,散発ポリマーの新しい発見です.
- 治療は,触媒化された PBD と触媒されていない PBD の間,および外部触媒の適用で観察されました.
結論:
- オレフィンメタテシスは,ポリマーの自己治癒のためのシンプルで効果的な方法を提供します.
- ルテニウム触媒によるアプローチは汎用性があり,様々なオレフィンを含むポリマーに適用できます.
- この方法は,より耐久性があり,修復可能なポリメリック材料を作成する可能性を開きます.
関連する概念動画
01:13Olefin Metathesis Polymerization: Overview
Recently, the development of olefin metathesis polymerization advanced the field of polymer synthesis. Simply put, the reorganization of substituents on their double bonds between two olefins in the presence of a catalyst is known as the olefin metathesis reaction. The use of metathesis reaction for polymer synthesis is called olefin metathesis polymerization.
Ruthenium-based Grubbs catalyst is the most commonly used catalyst for olefin metathesis polymerization. Grubbs catalyst consists of a...
Ruthenium-based Grubbs catalyst is the most commonly used catalyst for olefin metathesis polymerization. Grubbs catalyst consists of a...
00:53Olefin Metathesis Polymerization: Acyclic Diene Metathesis (ADMET)
Acyclic diene metathesis polymerization or ADMET polymerization involves cross-metathesis of terminal dienes, such as 1,8-nonadiene, to give linear unsaturated polymer and ethylene. As ADMET is a reversible process, the formed ethylene gas must be removed from the reaction mixture to complete the polymerization process.
Similar to cross-metathesis, ADMET also involves the formation of metallacyclobutane intermediate by [2+2] cycloaddition of one of the double bonds of a terminal diene with...
Similar to cross-metathesis, ADMET also involves the formation of metallacyclobutane intermediate by [2+2] cycloaddition of one of the double bonds of a terminal diene with...
01:16Olefin Metathesis Polymerization: Ring-Opening Metathesis Polymerization (ROMP)
Ring-opening metathesis polymerization or ROMP involves strained cycloalkenes as starting materials. The mechanism of ROMP proceeds by reacting cycloalkene with Grubbs catalyst to give metallacyclobutane intermediate which undergoes a ring-opening reaction to form new carbene. The new carbene reacts with another molecule of cycloalkene. Repetition of these steps leads to the formation of an unsaturated open-chain polymer product. All these steps are reversible, however, relieving the ring...
02:35Free-Radical Chain Reaction and Polymerization of Alkenes
The conversion of alkenes to macromolecules called polymers is a reaction of high commercial importance. The structure of the polymer is defined by a repeating unit, while the terminal groups are considered insignificant. The average degree of polymerization represents the number of repeating units in the polymer molecule and is denoted by the subscript n.
01:09Radical Chain-Growth Polymerization: Mechanism
The radical chain-growth polymerization mechanism consists of three steps: initiation, propagation, and termination of polymerization. The polymerization initiates when a free radical generated from the radical initiator adds to the unsaturated bond in the monomer. The unpaired electron of the free radical and one π electron in the unsaturated bond creates a σ bond between the free radical and the monomer. As a result, the other π electron in the unsaturated bond converts this species into the...
00:57Cationic Chain-Growth Polymerization: Mechanism
The cationic polymerization mechanism consists of three steps: initiation, propagation, and termination. In the initiation step of the polymerization process, the π bond of a monomer gets protonated by the Lewis acid catalyst, which is formed from boron trifluoride and water. The protonation of the π bond generates a carbocation stabilized by the electron‐donating group. In the propagation step, the π bond of the second monomer acts as a nucleophile and attacks the generated carbocation,...