関連する実験動画
Updated: Jul 19, 2025
08:12
Depolymerizable Olefinic Polymers Based on Fused-Ring Cyclooctene Monomers
Published on: December 16, 2022
3.4K
リング開き共ポリメリゼーション中のd-キシロース酸化物とカルボニル硫化物ベースのポリマーの構造変異in situ
David K Tran1, Ashley N Braaksma1, Autumn M Andras1
1Departments of Chemistry, Texas A&M University, College Station, Texas 77842, United States.
Journal of the American Chemical Society
|August 14, 2023
まとめ
d-キセロースとカルボニル硫化物 (COS) から持続可能なポリマーを合成した. 予期せぬバックボーン再構築により 独特の炭素酸とチオエーテルユニットが生み出され,熱安定性が向上し,分解性の高いプラスチックに 調節性特性を提供した.
科学分野:
- ポリマー化学
- 持続可能な材料科学
- 有機合成
背景:
- 再生可能資源から環境的に分解可能なプラスチックの開発は極めて重要です.
- C1原料による炭水化物の共ポリメリゼーションは,新しいポリマーへの持続可能な経路を提供します.
- ポリマーの骨格に硫黄を組み込むことで 材料の性質を調整できます
研究 の 目的:
- d-キセロースとカルボニル硫化物 (COS) から硫黄を含むポリマーを合成する.
- D-キセロース由来オクセタンとCOSのリング開き共聚合を調査する.
- 硫黄の組み込みがポリマーの特性や骨格構造に及ぼす影響を調査する.
主な方法:
- 3,5-アンヒドロ-1,2-O-イソプロピリデン-α-d-キシロフラーノースとカルボニル硫化物 (COS) のリング開き共ポリマー化.
- ポリメリゼーションのための (塩) CrCl/コカタリストシステムを使用した.
- フーリエ変換赤外線 (FTIR) と核磁共振 (NMR) スペクトロスコーピーを用いてポリマー構造と地域化学を特徴づけた.
主要な成果:
- 予期せぬ酸素/硫黄の交換と骨格の再構成が40°C以上で発生し,炭酸とチオエーテル二次単位を形成した.
- ポリマーの骨格組成は,温度と触媒/共触媒ステキオメトリーで調節可能であった.
- 硫黄を含むポリマーは,酸素同類と比較して熱安定性とガラス化温度の変化を示した.
結論:
- ダイナミック・バックボーン再構築は,調整可能な特性を持つ新しいd-キセロースベースのポリマーへの道を開きます.
- 硫黄の組み込みは熱安定性やガラス化温度に大きな影響を及ぼします.
- この作業は,天然の原料とCOSを使用して持続可能なポリマー生産を進めるものです.
関連する概念動画
01:16Olefin Metathesis Polymerization: Ring-Opening Metathesis Polymerization (ROMP)
2.6K
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...
2.6K
02:26Base-Catalyzed Ring-Opening of Epoxides
8.6K
Due to their highly strained structures, epoxides can readily undergo ring-opening reactions through nucleophilic substitution, either in the presence of an acid or a base. The nucleophilic substitution reactions in the presence of acid are called acid-catalyzed ring-opening reactions, and nucleophilic substitution reactions in the presence of a base are called base-catalyzed ring-opening reactions. Epoxides undergo base-catalyzed ring-opening reactions in the presence of a strong nucleophile...
8.6K
01:13Olefin Metathesis Polymerization: Overview
2.2K
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...
Ruthenium-based Grubbs catalyst is the most commonly used catalyst for olefin metathesis polymerization. Grubbs catalyst consists...
2.2K
02:24Acid-Catalyzed Ring-Opening of Epoxides
7.4K
Epoxides that are three-membered ring systems are more reactive than other cyclic and acyclic ethers. The high reactivity of epoxides originates from the strain present in the ring. This ring strain acts as a driving force for epoxides to undergo ring-opening reactions either with halogen acids or weak nucleophiles in the presence of mild acid. The acid catalyst converts the epoxide oxygen, a poor leaving group, into an oxonium ion, a better leaving group, making the reaction feasible. The...
7.4K
00:53Olefin Metathesis Polymerization: Acyclic Diene Metathesis (ADMET)
1.9K
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...
1.9K
03:00Preparation of Epoxides
7.8K
Overview
Epoxides result from alkene oxidation, which can be achieved by a) air, b) peroxy acids, c) hypochlorous acids, and d) halohydrin cyclization.
Epoxidation with Peroxy Acids
Epoxidation of alkenes via oxidation with peroxy acids involves the conversion of a carbon–carbon double bond to an epoxide using the oxidizing agent meta-chloroperoxybenzoic acid, commonly known as MCPBA. Since the O–O bond of peroxy acids is very weak, the addition of electrophilic oxygen of...
Epoxides result from alkene oxidation, which can be achieved by a) air, b) peroxy acids, c) hypochlorous acids, and d) halohydrin cyclization.
Epoxidation with Peroxy Acids
Epoxidation of alkenes via oxidation with peroxy acids involves the conversion of a carbon–carbon double bond to an epoxide using the oxidizing agent meta-chloroperoxybenzoic acid, commonly known as MCPBA. Since the O–O bond of peroxy acids is very weak, the addition of electrophilic oxygen of...
7.8K