Synthesis and Reactions of Strained Molecules and Polymers

应变分子和聚合物的合成与反应

• 批准号: 9617475
• 负责人: Kenneth Shea
• 金额: $ 39.2万
• 依托单位: University of California-Irvine
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-04-01 至 2000-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9617475&HistoricalAwards=false
• 关键词: Synthesis; Reactions; Strained; Molecules; Polymers

Professor Kenneth Shea, of the Department of Chemistry at the University of California, Irvine, is supported by the Organic Synthesis Program for his studies of the synthesis and reactions of strained molecules and polymers. Alkyl boranes initiate the polymerization of dimethylsulfoxonium methylide, resulting in the formation of perfectly linear polymethylene with an extremely narrow polydispersity index. Adjustment of the initial ratio of ylide to alkyl borane permits control of the molecular weight of the resulting polymethylene, while chemical transformations of the carbon-boron bonds of polyhomologated alkyl boranes allow the introduction of a variety of terminal functionalities. Extension of this polyhomologation chemistry to more complex alkyl borane initiators affords access to novel polymethylene architectures, including star, comb, and hyperbranched polymers. The chemistry may also be adapted to the formation of block copolymers which covalently link polymethylene with the incompatible polysiloxanes and polyethylene glycols. Development of control over the formation and structures of polymers, macromolecules comprised of chemically-linked repeating units derived from smaller molecules, is a central issue in the scientifically and technologically vital area of polymer chemistry. Professor Kenneth Shea exploits an unusual class of polymer-forming chemical reactions, wherein individual carbon atoms are added to a growing polymer chain one at a time. This chemistry affords synthetic access to a range of three-dimensional polymer structures, including circular-, comb-, and star-shaped materials, and will thereby permit the determination of the effects of such unusual structural motifs on the intrinsic and bulk properties of polymeric materials. Additional studies address the formation of block copolymers (two or more distinct polymers chemically linked to one-another) in which the linked polymers display drastically different properties. Unusual physical and chemical properties are expected to arise from such unions, including the formation of materials which can change their shapes and/or properties as a function of their environment.

大学化学系的肯尼斯·谢伊教授 加州州欧文市的有机合成计划支持， 他对应变分子的合成和反应的研究， 聚合物 烷基硼烷引发聚合反应， 二甲基亚砜甲基化物，导致形成完美的 具有极窄的多分散指数的线性聚亚甲基。 调节叶立德与烷基硼烷的初始比率允许控制 的分子量的所得聚亚甲基，而化学 多同系烷基的碳-硼键转化 硼烷允许引入各种末端官能团。 将这种多同系化化学扩展到更复杂的烷基硼烷 引发剂提供了新的聚亚甲基结构，包括 星星、梳形和超支化聚合物。 化学反应也可以是 适合于形成共价连接的嵌段共聚物 聚亚甲基与不相容的聚硅氧烷和聚乙烯 乙二醇。 发展对聚合物的形成和结构的控制， 由化学连接的重复单元组成的大分子 从更小的分子，是科学和 聚合物化学的技术关键领域。 Kenneth Shea教授 利用了一类不寻常的聚合物形成化学反应，其中 单个碳原子一个一个地被添加到生长的聚合物链中， 时间 这种化学反应提供了合成一系列 三维聚合物结构，包括圆形、梳形和 星型材料，从而允许确定 这种不寻常的结构图案对固有和体积的影响 聚合物材料的特性。 其他研究涉及 形成嵌段共聚物（两种或更多种不同的聚合物， 相互连接），其中连接的聚合物显示出显着的 不同的属性。 不寻常的物理和化学性质是 预计将产生这种工会，包括材料的形成， 其可以根据它们的形状和/或性质改变它们的形状和/或性质。 环境