富电子的金属能够合成高分子量,线性功能聚乙烯
Wei Zhang1, Peter M Waddell1, Margaret A Tiedemann1
1Department of Chemistry , Princeton University , Princeton , New Jersey 08544 , United States.
Journal of the American Chemical Society
|June 27, 2018
概括
新的二胺- (PDAP) 催化剂通过受控的电子效应使高分子量功能聚乙烯成为可能,克服了先进材料极性共聚合的关键挑战.
科学领域:
- 聚合物化学
- 催化剂
- 材料科学
背景情况:
- 第10组金属催化剂显示出对非极性和极性合聚合成功能材料的前景.
- 实现高共聚物分子重量仍然是实际应用的重大挑战.
研究的目的:
- 在极性聚合中开发控制共聚物分子重量的新策略.
- 研究新型化联体对催化共聚物的影响.
主要方法:
- 新型P(V) -P(III) 结合联体的合成和表征,特别是二胺联体 (PDAP).
- 用于乙烯和极性共聚变的单元催化剂,具有PDAP配体.
- 采用光谱,X射线晶体和计算方法来分析催化剂结构和行为.
主要成果:
- PDAP催化剂产生了直线性,功能性聚乙烯,其分子重量高达2×10^5gmol^-1,极性含量高达9mol%.
- 功能组主要沿着聚合物主链结合,模仿商业线性低密度聚乙烯.
- 分析显示PDAP的协调产生了与现有的催化剂系统不同,具有电子丰富的阴离子物种.
结论:
- 新型PDAP配体在极共聚化中提供了高分子量控制的新策略.
- 通过硬质效应补充的电子控制对于提高催化剂性能和避免共链的抑制至关重要.
- 这些发现推动了功能性聚乙烯的开发,
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