合成一种具有阳离子电荷的,高摩尔质量的第二代树化聚合物,并通过扫描力显微镜观察分支
Edis Kasëmi1, Wei Zhuang, Jürgen P Rabe
1Department of Materials, Institute of Polymers, Swiss Federal Institute of Technology, ETH-Hönggerberg, HCI J 541, 8093 Zürich, Switzerland.
Journal of the American Chemical Society
|April 13, 2006
概括
研究人员有效地合成了一种基于甲基酸盐的第二代树化宏观分子,并将其聚合成一种高分子质量的聚合物. 通过扫描力显微镜和NMR光谱学研究了这些树枝化聚合物的分支.
科学领域:
- 聚合物化学 聚合物化学
- 宏分子科学 宏分子科学
- 超分子化学 超分子化学
背景情况:
- 由于其分支架构,凝结聚合物具有独特的特性.
- 精确定义的树化聚合物的高效合成对于探索它们的应用至关重要.
- 控制分支和质量是了解聚合物行为的关键.
研究的目的:
- 描述第二代 (G2) 甲基酸基登德罗化宏观分子及其随后的聚合物的高效合成.
- 通过多种技术来表征由此产生的高摩尔质量G2凝结聚合物.
- 为了研究终端碳酸基的脱保护程度,并分析树枝化聚合物的分支.
主要方法:
- 丹德罗化宏观分子的自由基聚合.
- 使用凝透色谱 (GPC),光散射和分析超离心法来确定摩尔质量.
- 扫描力显微镜 (SFM) 用于轮长度分析和聚合物结构的成像.
- 核磁共振光谱法用于量化终端碳酸基的脱保护程度.
- 合成模型实验调查链接转移.
主要成果:
- 成功合成了一种G2树突化宏观分子,并将其聚合到高摩尔质量.
- 从GPC,光散射和超离心法获得的摩尔质量值与SFM估计值进行了比较.
- 核磁共振光谱学量化了 tert-butyl 保护的碳酸基的去保护.
- SFM成像揭示了大部分线性链,但也确定了主链分支,并调查了它们的性质和范围.
结论:
- 这项研究提供了一条有效的途径,以高摩尔质量登德罗化聚合物.
- 多种技术证实了聚合物的分子质量和结构特征.
- 在这些树化聚合物中进行了分支的特征,一个模型实验提供了对链接转移等潜在分支机制的见解.
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