循环乙烯碳酸的催化环开放聚合:通过使用动力测量验证的DFT-MTD模拟揭示了确定聚合物性能的基本步骤的重要性
Daniel Brüggemann1,2, Martin R Machat2,3, Reinhard Schomäcker1
1Institut für Chemie-Technische Chemie, Technische Universität Berlin, Straße des 17. Juni 124, D-10623 Berlin, Germany.
Polymers
|January 11, 2024
概括
这项研究揭示了催化剂如何控制二氧化碳聚合物合成. 催化剂转移机制决定了聚合物的分子量和链条寿命,从而能够精确控制含有二氧化碳的聚合物生产.
科学领域:
- 聚合物化学 聚合物化学
- 计算化学的计算化学
- 材料科学 材料科学 材料科学
背景情况:
- 控制含有二氧化碳的聚合物中的二氧化碳含量和分子量仍然具有挑战性.
- 循环乙烯碳酸盐 (cEC) 的催化环开放聚合提供了这些聚合物的途径.
- 对CEC聚合物的反应机制和控制参数尚未完全理解.
研究的目的:
- 阐明聚合过程中催化剂-cEC相互作用的机制.
- 为了研究在传播阶段释放的二氧化碳.
- 了解催化剂如何影响聚合物分子量和链条寿命.
主要方法:
- 密度函数理论 (DFT) 的元动力学模拟.
- 动力测量以确认模拟结果.
- 分析催化剂与CEC单体和聚合物链的相互作用.
主要成果:
- 催化剂与聚合物链的连接可以是可逆的,定义激活链的寿命.
- 在cEC单体之间的催化剂转移控制链的终结和启动.
- 催化剂特性影响可逆性和转移机制.
结论:
- 催化剂转移机制是控制cEC聚合过程中分子重量的关键.
- 了解这些机制允许精确合成含有二氧化碳的聚合物.
- 这项工作为定制聚合物生产的催化剂行为提供了洞察力.
更多相关视频
相关概念视频
Olefin Metathesis Polymerization: Overview
2.1K
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...
2.1K
Thermal Electrocyclic Reactions: Stereochemistry
2.0K
The stereochemistry of electrocyclic reactions is strongly influenced by the orbital symmetry of the polyene HOMO. Under thermal conditions, the reaction proceeds via the ground-state HOMO.
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.
2.0K
Olefin 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
Olefin 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
Diels–Alder Reaction Forming Cyclic Products: Stereochemistry
3.9K
The Diels–Alder reaction is one of the robust methods for synthesizing unsaturated six-membered rings. The reaction involves a concerted cyclic movement of six π electrons: four π electrons from the diene and two π electrons from the dienophile.
3.9K
Base-Catalyzed Ring-Opening of Epoxides
8.5K
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...
8.5K


