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首页> 外文学位 >Star and cyclic shaped macromoleculars architectures prepared using copper-catalyzed azide-alkyne cycloaddition: Synthesis, purification and characterization.
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Star and cyclic shaped macromoleculars architectures prepared using copper-catalyzed azide-alkyne cycloaddition: Synthesis, purification and characterization.

机译：使用铜催化的叠氮化物-炔烃环加成反应制备的星形和环状高分子结构：合成，纯化和表征。

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摘要

The use of advanced functional polymer materials has gained an enormous impact during the past decades. Due to the fact that the physical properties of macromolecules are inherently dependent on their structure and connectivity on the nanoscale, precisely control over polymer architecture has been a longstanding goal for polymer chemists. The recent development of copper catalyzed azide-alkyne click chemistry provides a nearly quantitatively tool for macromolecular coupling. Through the combination of living polymerization and click chemistry, novel complex polymer architectures can be readily constructed, including star polymers, brush polymers, cyclic polymer and ladder polymers.;While amphiphilic block copolymers have demonstrated their utility for a range of practical applications, the behavior of block copolymers that contain cyclic topologies remains largely unexplored due to limited synthetic access. In order to investigate their micelle formation, biocompatible cyclic amphiphilic poly(ethylene glycol)-block-polycaprolactone, c-(PEG- b-PCL), and tadpole shaped PEG-PCL, were synthesized by a combination of ring opening polymerization (ROP) and click chemistry. In addition, exactly analogous linear block copolymers have been prepared as control samples to elucidate the role of polymer architecture in their self-assembly and acid-catalyzed degradation.;High purity homo-arm and mikto-arm poly(ethylene glycol) (PEG) stars were successfully prepared by the combination of epoxide ring openings and azide-alkyne click reactions. First, monohydroxy-PEG was modified via epoxide chemistry to bear one hydroxyl and one azide functionality at the same polymer chain end. An alkyne functionalized PEG chain was then coupled to the azide. Subsequently, the remaining hydroxyl could be reactivated by epoxide chemistry again to an azide and alcohol group. This enabled a step-wise coupling and reactivation of the end group to add a series of well-defined polymer arms onto a star polymer. The use of efficient reactions for this iterative route provided star polymers with an exact number of arms, and a tailorable degree of polymerization for each arm. Detailed characterization confirmed the high purity of multi-arm polyethylene glycol products.;Novel cyclic brush-shaped polymers can be successfully prepared by using the CuAAC click coupling reaction. First, cyclic-shaped polymer bearing a single hydroxyl group can be synthesized by CuAAC click cyclization. After a one-step modification of the hydroxyl group by esterification with an azido-carboxylic acid, a "clickable" polymer ring was obtained. A linear polymer backbone with an alkyne functional group on every repeat unit was prepared by ATRP of acetoxystyrene followed by reduction to poly(4-hydroxystyrene) and esterification with pentynoic acid. Finally, by coupling multiple equivalents of the cyclic precursor onto the linear backbone, a cyclic brush-shaped polymer was prepared. This provides a highly efficient approach to prepare novel polymer architectures containing multiple cyclic components.
机译：在过去的几十年中，先进的功能聚合物材料的使用已产生了巨大的影响。由于大分子的物理性质固有地取决于其在纳米尺度上的结构和连通性，因此对聚合物结构的精确控制一直是高分子化学家的长期目标。铜催化的叠氮化物-炔点击化学的最新进展为大分子偶联提供了几乎定量的工具。通过活性聚合和点击化学的结合，可以轻松构建新型复杂的聚合物结构，包括星形聚合物，刷型聚合物，环状聚合物和梯形聚合物。虽然两亲嵌段共聚物已证明其在一系列实际应用中的实用性，但其行为由于有限的合成途径，大部分含有环状拓扑的嵌段共聚物仍未得到开发。为了研究它们的胶束形成，通过开环聚合（ROP）的组合，合成了生物相容性环状两亲性聚乙二醇嵌段聚己内酯c-PEG-b-PCL和t形PEG-PCL。然后点击化学。此外，已经制备了完全相似的线性嵌段共聚物作为对照样品，以阐明聚合物结构在其自组装和酸催化降解中的作用。;高纯度均臂和mikto-arm聚乙二醇（PEG）通过环氧化物的开环和叠氮化物-炔的点击反应的结合成功地制备了恒星。首先，通过环氧化学修饰单羟基-PEG，使其在同一聚合物链末端具有一个羟基和一个叠氮官能团。然后将炔官能化的PEG链偶联至叠氮化物。随后，剩余的羟基可以通过环氧化学再次活化为叠氮化物和醇基团。这使得端基可以逐步偶联和再活化，从而在星形聚合物上添加一系列定义明确的聚合物臂。在此迭代路线中使用有效的反应可为星形聚合物提供精确的臂数，以及每个臂可定制的聚合度。详细的表征证实了多臂聚乙二醇产品的高纯度。通过使用CuAAC点击偶联反应可以成功制备新型环状刷状聚合物。首先，可以通过CuAAC点击环化来合成带有单个羟基的环状聚合物。通过用叠氮基羧酸酯化一步改性羟基后，获得“可点击的”聚合物环。通过乙酰氧基苯乙烯的ATRP，然后还原为聚（4-羟基苯乙烯）并用戊酸酯化，制备在每个重复单元上具有炔官能团的线性聚合物主链。最后，通过将多个当量的环状前体偶联到线性骨架上，制备环状刷状聚合物。这提供了一种高效的方法来制备包含多个环状组分的新型聚合物结构。

著录项

  • 作者

    Zhang, Boyu.;

  • 作者单位

    Tulane University School of Science and Engineering.;

  • 授予单位 Tulane University School of Science and Engineering.;
  • 学科 Polymer chemistry.
  • 学位 Ph.D.
  • 年度 2015
  • 页码 222 p.
  • 总页数 222
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类 物理化学（理论化学）、化学物理学;
  • 关键词

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