Dynamic Multi-state Living Coordination Polymerization for Next Generation Polyolefins

下一代聚烯烃的动态多态活性配位聚合

• 批准号: 2247554
• 负责人: Lawrence Sita
• 金额: $ 57.5万
• 依托单位: University of Maryland, College Park
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-05-01 至 2026-04-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2247554&HistoricalAwards=false
• 关键词: Dynamic; Multi; state; Living; Coordination

With the support of the Chemical Catalysis (CAT) and the Macromolecular, Supramolecular, and Nanochemistry (MSN) Programs in the Division of Chemistry, Professor Lawrence Sita of the University of Maryland, College Park is developing new polymerization catalysts that can be programmed to deliver multiple products from a single initiator. This ‘one catalyst – many materials’ paradigm is being investigated to expand the range of new polyolefin materials that possess technologically-useful physical properties that are of benefit to society and the economy, such as recyclability and serving as replacements for less environmentally benign legacy plastics. Group 4 catalysts are being tuned to undergo selective polymerization in systems that would typically be assumed to be unselective. The activities that are being pursued also provide an excellent forum for training the next generation of scientists for science- and engineering-related careers in education, industry, and science policy, and importantly, those who are members of underrepresented groups.Homogeneous olefin polymerization catalysts are traditionally optimized to produce a single type of polymer from a single monomer. In contrast, Professor Sita and his research team are designing and preparing Group 4 d(0)-complexes supported by cyclopentadienyl and amidinate ligands that can serve as initiators for the living coordinative chain transfer polymerization of olefins into multiple new classes of polyolefin products. By exerting control over the relative rates of reversible dynamic reactions that are competitive with chain-growth propagation, highly versatile multi-state polymerization processes are being programmed to deliver a spectrum of different products from a single initiator under otherwise identical conditions. Different controlling elements of the system being explored include: the structure and chirality of the amidinate ligands, the effect of coordinative groups installed on the amidinate ligands, as well as reaction mixture temporal control over polymer composition. These studies are working towards the advance of polyolefin materials with desirable physical properties while establishing new elements of catalytic control in complex systems.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

在化学催化（CAT）和大分子，超分子和纳米化学（MSN）计划的支持下，马里兰州大学公园的劳伦斯·西塔（Lawrence Sita）教授正在开发新的聚合催化剂，这些催化剂可以从单个启动器中进行编程以从单个启动器中进行编程。正在研究这种“一种催化剂 - 许多材料”范式，以扩大具有具有技术用途的物理特性的新材料，这些物理特性对社会和经济有益，例如可回收性和作为替代环境较少的良性遗产塑料的替代品。第4组催化剂被调整为在系统中通常被认为是无可有效的系统中进行选择性聚合。正在从事的活动还为培训下一代科学家在教育，工业和科学政策方面从事科学和工程有关的职业提供了一个良好的论坛，重要的是，那些人数不足的人的成员是烯烃聚集催化剂。传统上是最优化的，可以从单个单体物体中产生一种单一类型的聚合物。相比之下，SITA教授及其研究团队正在设计和准备4 d（0）组合物，由环戊二烯基和胺氨酸配体支持，这些配体可以用作生命协调的链链转移聚合到多种新类聚素产品的链链转移聚合。通过控制与链增长传播具有竞争力的可逆动态反应的相对速率，正在对高度用途的多状态聚合过程进行编程，以在与众不同的条件下从单个引发剂中传递不同产品。正在探索的系统的不同控制元素包括：胺化配体的结构和手性，安装在胺化配体上的协调组的效果以及对聚合物组成的反应混合物临时控制。这些研究正在为具有理想的物理特性的聚烯材料的发展而努力，同时在复杂系统中建立了新的催化控制元素。该奖项反映了NSF的法定任务，并通过使用基金会的知识分子和更广泛的影响审查标准来通过评估来获得珍贵的支持。