对热稳定性的拓导向控制:由线性和循环式两类块共聚合物形成的微粒
Satoshi Honda1, Takuya Yamamoto, Yasuyuki Tezuka
1Department of Organic and Polymeric Materials, Tokyo Institute of Technology, O-okayama, Meguro-ku, Tokyo 152-8552, Japan.
Journal of the American Chemical Society
|July 29, 2010
概括
将线性聚合物转换为循环结构显著提高了微粒的热稳定性. 聚合物两体的这种拓变化使云点温度 (Tc) 提高了40摄氏度以上.
科学领域:
- 聚合物化学 聚合物化学
- 材料科学 材料科学 材料科学
- 物理化学 物理化学
背景情况:
- 自组装的米塞尔在各种应用中至关重要,但它们的热稳定性可能是一个限制.
- 聚合物拓学,例如线性与循环结构,可以影响材料特性.
- 了解拓变化如何影响微粒的行为是设计先进材料的关键.
研究的目的:
- 调查聚合物拓对自组装微粒的热稳定性的影响.
- 为了比较由线性和循环聚合物两类分子形成的微粒的特性.
- 通过共同组装探索微粒热稳定性的可调性.
主要方法:
- 线性和循环的聚乙烯基酸-块聚乙烯氧化-块聚乙烯基酸聚合物的合成.
- 在水溶液中通过自我组装形成菌.
- 粘度测量用于确定关键菌度 (CMCs).
- 动态光散射 (DLS),原子力显微镜 (AFM) 和传输电子显微镜 (TEM) 用于微粒的表征.
- 测量云点温度 (Tc),以评估热稳定性.
主要成果:
- 线性聚合物和循环聚合物都形成了直径约20nm的球形花样小粒.
- 对线性 (0.13 mg/mL) 和周期性 (0.14 mg/mL) 聚合物而言,临界微粒度相似.
- 与线性聚合物相比,由循环聚合物形成的微粒的云点温度 (Tc) 升高了40摄氏度以上.
- 线性和循环聚合物的联合组装允许调整微粒云点温度.
结论:
- 从线性转化为循环的聚合物形分子的拓转化显著提高了微粒的热稳定性.
- 观察到的云点温度增加归因于拓效应,而不是化学成分或微粒结构的变化.
- 联合组装提供了一种方法,可以精确控制聚合物微粒的热特性.
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