使用过渡金属催化剂对化乙烯和乙烯酸乙烯与乙烯的共聚化研究
Harold W Boone1, Phillip S Athey, Michael J Mullins
1The Dow Chemical Company, Corporate R&D, 2301 North Brazosport Boulevard, B-3814 Freeport, Texas 77541-3257, USA.
Journal of the American Chemical Society
|July 26, 2002
概括
这项研究探讨了使用新型催化剂与乙烯化物 (VC) 和乙烯酸乙烯 (VA) 的乙烯共聚化. 虽然VC和VA合并,但它们的存在通过β消除终止了链的生长.
科学领域:
- 聚合物化学 聚合物化学
- 有机金属催化工艺
- 协调聚合的聚合物.
背景情况:
- 齐格勒-纳塔聚合方式彻底改变了乙烯聚合的过程.
- 将协调聚合扩展到极性单体仍然是一个挑战.
- 极性单体对于开发功能化的多聚烯来说至关重要.
研究的目的:
- 为了研究乙烯与乙烯酸 (VC) 和乙烯酸乙烯 (VA) 的共聚合.
- 为了评估这个过程的三酸铁二二二二二胺催化剂.
- 了解VC和VA的合并行为和链终结机制.
主要方法:
- 无化乙烯与无化乙烯和乙烯酸乙烯的联合聚合.
- 使用了一种特定的三酸铁二二二二二胺金属催化剂.
- 使用气体染色学/质谱学 (GC/MS) 和核磁共振 (2H NMR) 光谱学分析得到的乙烯寡合物.
主要成果:
- 乙烯化物 (VC) 被纳入以大约1:180的乙烯单体的比例.
- 乙乙酸乙烯 (VA) 被纳入以大约1:350乙烯单体的比例.
- 两者VC和VA都充当了comonomers,但通过β-消除诱导了链末端,其中仅在烯酸末端.
结论:
- 铁II催化剂有助于将VC和VA有限地纳入乙烯链中.
- 在结合VC或VA时,β消除是重要的链终结途径.
- 这项研究强调了在协调聚合过程中实现极性单体的高整合方面的挑战.
相关概念视频
Catalysis
The presence of a catalyst affects the rate of a chemical reaction. A catalyst is a substance that can increase the reaction rate without being consumed during the process. A basic comprehension of a catalysts’ role during chemical reactions can be understood from the concept of reaction mechanisms and energy diagrams.
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...
Heterogeneous Catalysis
Heterogeneous catalysis involves a catalyst in a different phase from the reactants. It is a process where the catalyst and the reactants are in distinct phases, typically solid and gas or liquid.Most heterogeneous catalysts are metals, metal oxides, or acids. The list includes transition metals like iron (Fe), cobalt (Co), nickel (Ni), palladium (Pd), platinum (Pt), chromium (Cr), manganese (Mn), tungsten (W), silver (Ag), and copper (Cu). These metals possess partially vacant d orbitals that...


