用基于Zn ((C6F5) 2) 的易斯对进行环开聚合:对循环聚合物的原始和高效方法
Estefanía Piedra-Arroni1, Catherine Ladavière, Abderrahmane Amgoune
1Laboratoire Hétérochimie Fondamentale et Appliquée, UMR CNRS 5069, Université de Toulouse , F-31062 Toulouse, France.
Journal of the American Chemical Society
|August 31, 2013
概括
采用和有机基的双催化剂系统,可以控制乳酸盐和酸盐的聚合. 这种方法可以产生高分子量循环聚合物和循环块共聚合物.
科学领域:
- 聚合物化学 聚合物化学
- 有机金属化学 有机金属化学
背景情况:
- 环开聚合 (ROP) 是合成聚的关键方法.
- 控制的ROP对于定制聚合物特性和创建复杂架构至关重要.
- 易斯酸/基对为单体聚合提供了独特的激活机制.
研究的目的:
- 调查乳化物和e-caprolactone的受控ROP的双催化剂系统.
- 探索复合物和有机基在聚合过程中的合作作用.
- 合成精确定义的循环聚合物和块共聚合物.
主要方法:
- 使用包括Zn(C6F5) 2和有机基 (氨基,素) 的双系统.
- 进行受控的乳化物和e-caprolactone的环开聚合.
- 采用链延长技术用于块共聚合物合成.
主要成果:
- 双重系统有效地促进了两种单体的受控ROP.
- 得到了具有高分子量的精确定义的循环聚合物.
- 高效的链延伸导致了循环块共聚合物的形成.
结论:
- 合作性易斯对Zn ((C6F5) 2) 和有机基对受控的ROP非常有效.
- 这种方法可以获得高分子量循环聚合物和块共聚合物.
- 开发的方法为先进的聚合物架构提供了一条途径.
相关概念视频
Olefin 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...
Ziegler–Natta Chain-Growth Polymerization: Overview
Ziegler–Natta polymerization is another form of addition or chain‐growth polymerization used for synthesizing linear polymers over branched polymers. The catalyst used for polymerization is the Ziegler–Natta catalyst, named after Karl Ziegler and Giulio Natta, who developed it in 1953. This catalyst is an organometallic complex of titanium tetrachloride and triethyl aluminum, with the active form of the catalyst being an alkyl titanium compound. Using the Ziegler–Natta catalyst, high molecular...
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,...
Base-Catalyzed Ring-Opening of Epoxides
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...
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...
Free-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.


