核基模板聚合:复制活聚合物的链长和聚分散性,将其转化为联聚合物
Pik Kwan Lo1, Hanadi F Sleiman
1Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montreal, Quebec, H3A 2K6, Canada.
Journal of the American Chemical Society
|March 12, 2009
概括
这项研究引入了核基模板聚合,这是一种合成合聚合物的新方法. 它精确地控制了聚合物链长度和分子量分布,克服了传统方法的局限性.
科学领域:
- 聚合物化学 聚合物化学
- 有机合成 有机合成
- 材料科学 材料科学 材料科学
背景情况:
- 步骤聚合通常会产生具有较差分子量控制和广泛分布的合聚合物.
- 生物聚合方法提供了更好的控制,但并不总是适合所有的聚合物类型.
研究的目的:
- 开发一种用于合成具有受控分子量和狭窄分布的合聚合物的新方法.
- 利用核基识别用于模板聚合物合成,将特征从母聚合物转移到子聚合物.
主要方法:
- 采用含核基的单体,这些单体通过键对齐在一个互补的母聚合物模板上.
- 在对齐的单体上进行Sonogashira聚合,以创建子结合聚合物.
- 将模板聚合与非模板聚合进行比较,并使用不正确的模板进行聚合.
主要成果:
- 核基模板聚合成功产生了与母模板相似的狭窄分子量分布和长度的子联聚合物.
- 非模板聚合或与不匹配模板的聚合导致较短的合寡合体,具有显著更广泛的分子量分布.
- 从活体聚合物模板转移到结合聚合物,证明了受控的链条长度和狭窄的分子量分布.
结论:
- 核基模板聚合是一种有效的策略,用于合成具有精确结构控制的合聚合物.
- 这种方法允许精确编程聚合物结构,长度和分子量分布,增强聚合物特性.
- 它弥合了受控活体聚合技术和对联聚合物的传统阶段聚合方法之间的差距.
相关概念视频
Anionic Chain-Growth Polymerization: Mechanism
The mechanism for anionic chain-growth polymerization involves initiation, propagation, and termination steps. In the initiation step, a nucleophilic anion, such as butyl lithium, initiates the polymerization process by attacking the π bond of the vinylic monomer. As a result, a carbanion, stabilized by the electron‐withdrawing group, is generated. The resulting carbanion acts as a Michael donor in the propagation step and attacks the second vinylic monomer, which acts as a Michael acceptor.
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,...
Step-Growth Polymerization: Overview
Step-growth or condensation polymerization is a stepwise reaction of bi or multifunctional monomers to form long-chain polymers. As all the monomers are reactive, most of the monomers are consumed at the early stages of the reaction to form small chains of reactive oligomers, which then combine to form long polymer chains in the late stages. Hence, the reaction has to proceed for a long time to achieve high molecular weight polymers.
Many natural and synthetic polymers are produced by...
Many natural and synthetic polymers are produced by...
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The word polymer is derived from the Greek words “poly” which means “many” and “mer” which means “parts”. Polymers are long chains of molecules composed of repeating units of smaller molecules, known as monomers. They either occur naturally, such as DNA and proteins, or can be constructed synthetically, like plastics. They have varied structural characteristics, such as linear chains, branched chains, or complex networks, that contribute to the properties that they exhibit. Additionally,...
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The word polymer is derived from the Greek words “poly” which means “many” and “mer” which means “parts”. Polymers are long chains of molecules composed of repeating units of smaller molecules, known as monomers. They either occur naturally, such as DNA and proteins, or can be constructed synthetically, like plastics. They have varied structural characteristics, such as linear chains, branched chains, or complex networks, that contribute to the properties that they exhibit. Additionally,...
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The word polymer is derived from the Greek words “poly” which means “many” and “mer” which means “parts”. Polymers are long chains of molecules composed of repeating units of smaller molecules, known as monomers. They either occur naturally, such as DNA and proteins, or can be constructed synthetically, like plastics. They have varied structural characteristics, such as linear chains, branched chains, or complex networks, that contribute to the properties that they exhibit. Additionally,...


