コバルト ((III)) ベースの触媒システムを使用して,CO2とエピクロロヒドリンの完全な交互の共ポリメリゼーション
Guang-Peng Wu1, Sheng-Hsuan Wei, Wei-Min Ren
1State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian, People's Republic of China.
Journal of the American Chemical Society
|August 23, 2011
まとめ
この研究は,新しいコバルト触媒を用いて二酸化炭素とエピクロロヒドリンから生物分解性ポリカーボネートの効率的な合成を実証しています. この研究は,電子欠乏エポキシドによる選択的共ポリメリゼーションの課題を強調しています.
科学分野:
- ポリマー化学のポリマー化学について
- グリーン・ケミストリー 緑の化学
- カタリシス カタリシス カタリシス
背景:
- エポキシドとのコポリメリゼーションによる二酸化炭素利用は,生物分解性ポリカーボネートを生成します.
- 以前の研究では主にアリファティックエポキシドが用いられ,エピクロロヒドリンのような電子取り除く基を持つエポキシドの成功は限られていた.
- 多種多様なエポキシドによるCO2共ポリメリゼーションのための効率的な触媒の開発は,持続可能な化学合成に不可欠です.
研究 の 目的:
- エピクロロヒドリンとCO2を用いたCO2共ポリマーの選択的合成を報告する.
- エピクロロヒドリンとプロピレン酸化物のサイクル炭酸とポリ炭酸形成の運動的差異を調査する.
- 先進的な分析技術を用いて,CO2/エピクロロヒドリンの共ポリメリゼーションのメカニズムを解明する.
主な方法:
- 二酸化炭素とエピクロロヒドリンのCO2とエピクロロヒドリンの交代共ポリメリゼーションは,バイナリと二機能 (塩) コバルト (III) 触媒を用いて行われます.
- In situ赤外線スペクトロスコーピーは,サイクル炭酸塩とコポリマー形成の比喩的な運動研究を行います.
- ポリマー鎖の種を直接観察するための電子スプレーイオン化質量スペクトロメトリー (ESI-MS).
主要な成果:
- エピクロロヒドリンから,99%以上の炭酸結合を持つCO2共ポリマーの製造.
- 運動分析は,プロピレン酸化物 (53.5 kJ/mol) と比較して,エピクロロヒドリン (45.4 kJ/mol) との共ポリメリゼーションの活性化エネルギー差が小さいことを明らかにし,選択的共ポリマー合成の難しさが大きいことを示した.
- ESI-MSは,得られたコポリマーの完全な交互構造を確認し,MTBDを含む潜在的な中間物質を提案しました.
結論:
- この研究では,CO2とエピクロロヒドリンから高純度ポリカーボネートを成功裏に生成し,CO2利用の有意な進歩を示しました.
- 運動的洞察は,電子欠乏エポキシドによる選択的共ポリメリゼーションの課題を説明する.
- この発見は,CO2ベースのポリマー合成のためのより効率的な触媒を開発するためのメカニズム的基盤を提供します.
さらに関連する動画
関連する概念動画
Preparation of Epoxides
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 peroxy acids to...
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 peroxy acids to...
Characteristics and Nomenclature of Copolymers
Copolymers are the products obtained from the polymerization of multiple monomer species. So, in a polymer chain itself, there can be multiple repeating units that come from different monomers. The process of synthesizing a polymer from different monomer species is called copolymerization. When two monomers are involved, the polymer is known as a bipolymer. Polymers with three and four monomers are termed terpolymers and quaterpolymers, respectively. Figure 1 depicts the copolymerization of...
Sharpless Epoxidation
The conversion of allylic alcohols into epoxides using the chiral catalyst was discovered by K. Barry Sharpless and is known as Sharpless epoxidation. The use of a chiral catalyst enables the formation of one enantiomer of the product in excess. This chiral catalyst is mainly a chiral complex of titanium tetraisopropoxide and tartrate ester (specific stereoisomer). The stereoisomer used in the chiral catalyst dictates the formation of the enantiomer of the product. In other words, the use of...
Cationic 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,...
Olefin 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...
Acid-Catalyzed Ring-Opening of Epoxides
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...


