物理衰老和玻璃过渡在玻璃-聚合物双层膜中的比较
Jennifer A McGuire1, James H Merrill1, Alexander A Couturier1
1Department of Physics, Emory University, Atlanta, Georgia 30322, United States.
The journal of physical chemistry. B
|March 3, 2025
概括
薄聚乙烯 (PS) 薄膜的物理老化不受性聚甲基酸 (PnBMA) 接口的影响,即使在75nm. 这一令人惊的发现挑战了关于聚合物动态界面影响的先前假设.
科学领域:
- 聚合物科学 聚合物科学
- 材料科学 材料科学 材料科学
- 物理化学 物理化学
背景情况:
- 软接口对玻璃聚合物领域物理衰老的影响仍然不太清楚.
- 之前的研究表明,聚合物接口显著降低了相邻玻璃层的玻璃过渡温度 (Tg).
- 众所周知,自由表面会影响身体衰老,这表明接口可能具有明显的影响.
研究的目的:
- 为了研究聚乙烯 (PS) 薄层在状玻璃聚乙烯 (PnBMA) /PS双层薄膜中的物理衰老反应.
- 为了确定软PnBMA/PS接口是否会改变PS的物理衰老,正如接口Tg低压所预测的那样.
- 为了比较有限双层膜中的PS的老化行为与散装行为和以前的半无限系统发现.
主要方法:
- 圆测量用于测量薄聚钢 (PS) 层的物理衰老反应.
- 使用光测量来确定PS层的平均玻璃过渡温度 (Tg).
- 在PS上PnBMA的双层薄膜被制造成不同厚度的层.
主要成果:
- 在PS层的物理衰老反应仍然相当于散装行为,直到75nm最薄的可测厚度.
- 在150nm PnBMA/75nm PS 薄膜中,PS 层的平均玻璃过渡温度 (Tg) 也被发现是散装的.
- 与预期相反,软PnBMA/PS接口并没有显著改变薄PS层的物理老化.
结论:
- 双层结构中的薄玻璃型聚合物薄膜与半无限系统相比,呈现出明显的界面动态梯度.
- 聚乙烯的物理衰老令人惊地强大,并且在研究的厚度下不受相邻的状聚 ((n-基甲酸) 接口的显著影响.
- 聚合物薄膜中的有限域大小导致改变的界面动态,与基于半无限模型的预测不同.
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