関連する実験動画
Updated: Mar 14, 2026

08:12
Depolymerizable Olefinic Polymers Based on Fused-Ring Cyclooctene Monomers
Published on: December 16, 2022
4.0K
単一モノマー添加に基づく生変環開拓メタテシスポリメリゼーション
1Department of Chemistry, Stanford University, Stanford, California 94305, United States.
Journal of the American Chemical Society
|July 17, 2015
まとめ
分置されたサイクロプロペンは,リング開きメタテシスを通して,サイクルオレフィンとの制御された生変異ポリメリゼーションを可能にします. この方法は,正確な分子量と微細構造を持つポリマーを生成し,副作用を回避します.
科学分野:
- ポリマー化学
- 有機合成
- 材料科学
背景:
- リングオープニングメタテシスポリメリゼーション (ROMP) は,ポリマー合成のための多用途技術である.
- 制御された生体ポリメリゼーションと交互の共ポリメリゼーションを達成することは,特定のモノマーにとって課題である.
研究 の 目的:
- 制御可能なROMPのための新型のサイクロプロペンのモノマーを開発する.
- 低ストレスのサイクルオレフィンによる生変環開拓メタテシスポリメリゼーション (ROMP) を達成する.
- ポリメリゼーションにおける解置換サイクロプロペンの運動的振る舞いを調査する.
主な方法:
- 特別に設計されたシクロプロペンの合成
- 様々な低ストレスのサイクルオレフィンによるリング開きメタテシスポリメリゼーション (ROMP).
- NMRスペクトル (1Hと13C) とMALDI-TOFMSを用いた特徴づけ
主要な成果:
- ディスブスチューテッドサイクロプロペンは選択的にROMPで単一モノマー添加を受けます.
- 低ストレスのサイクルオレフィンとROMPを交互に生かして,制御された分子量と低分散性を有するポリマーが得られる.
- 高度な微細構造の規則性と,結果として得られる共ポリマーにおける厳格な交替のシーケンスを示した.
- 代謝されたサイクロプロペンの0次動力学が観察され,初期添加が迅速であることを示した.
結論:
- サイクロプロペンのリングストレスの合理的な調節は,ROMPの制御の鍵です.
- このアプローチは,明確に定義された交互のコポリマーを合成するための強力な新しい経路を提供します.
- 開発された方法は,ポリマーの構造と特性に対する正確な制御を提供します.
関連する概念動画
Olefin Metathesis Polymerization: Ring-Opening Metathesis Polymerization (ROMP)
3.3K
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...
3.3K
Olefin Metathesis Polymerization: Overview
2.7K
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...
2.7K
Olefin Metathesis Polymerization: Acyclic Diene Metathesis (ADMET)
2.3K
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...
2.3K
Radical Chain-Growth Polymerization: Overview
3.6K
Chain-growth or addition polymerization is successive addition reactions of monomers with a polymer chain. In radical chain-growth polymerization, the reaction proceeds via a free-radical intermediate. The free radical is formed from radical initiators, which spontaneously generate free radicals by homolytic fission. Organic peroxides (such as dibenzoyl peroxide, as shown in Figure 1) or azo compounds are popular radical initiators. A low concentration ratio of radical initiator to monomer is...
3.6K
Cationic Chain-Growth Polymerization: Mechanism
3.0K
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...
3.0K
Radical Chain-Growth Polymerization: Mechanism
3.7K
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...
3.7K

