通过比较两种同位素双二二胺基衍生出来的homo-polyimide膜
Meng Lian1, Feng Zheng2, Lingbin Meng1
1Shandong Engineering Laboratory for Clean Utilization of Chemical Resources, Weifang University of Science and Technology, Weifang 262700, China.
Molecules (Basel, Switzerland)
|July 14, 2023
概括
氨基基组在基于本齐米达的聚胺中的位置显著影响了它们的特性. 与3-AB相比,含有4-AB的聚化物表现出优越的机械性能和较低的热膨胀.
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
- 有机化学 有机化学
背景情况:
- 带有本齐米达单元的异芳性聚合物 (PI) 提供了增强的特性.
- 已经对含有4,4'-[5,5'-bi-1H-benzimidazole]-2,2'-diylbis-benzenamine (4-AB) 的PI进行了研究,但对其同位素3,3'-[5,5'-bi-1H-benzimidazole]-2,2'-diylbis-benzenamine (3-AB) 没有进行研究.
研究的目的:
- 为了研究氨基组定位异构体 (3-AB与4-AB) 对同型聚胺的性能的影响.
- 为了比较来自3-AB和4-AB的PI的机械性能,热行为和光学特性.
主要方法:
- 使用3-AB和4-AB异构体合成同型聚胺.
- 机械性能,热稳定性 (T_g,5%的减肥温度) 和热膨胀系数 (CTE) 的实验性表征.
- 分子模拟用于分析形状差异和电子性质.
主要成果:
- 由于其氨基的净电荷较低,4-AB表现出更高的反应性,从而使相应的PI具有更好的机械性能.
- 分子模拟显示了3-AB及其PI链的扭曲形状,导致更浅的PI膜.
- 与4-AB相比,3-AB的PI显示出更高的旋转能量和玻璃过渡温度 (T_g > 400 °C).
- 来自4-AB的PI显示出更大的分子线性,导致更低的热膨胀系数 (CTE).
- 所有合成的PI都显示出出色的热稳定性,体重减轻5%的温度高于530°C.
结论:
- 胺单体的位置性异构在很大程度上决定了聚胺的最终性质.
- 基于4-AB的PI在机械强度和尺寸稳定性 (较低的CTE) 中具有优势.
- 基于3-AB的PI提供更高的热电阻 (更高的T_g) 和独特的光学性能.
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