在低密度和高密度聚乙烯中的放松现象
Viktor A Lomovskoy1, Svetlana A Shatokhina1
1Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences (IPCE RAS), Leninskiy Prospekt 31, 119071 Moscow, Russia.
Polymers
|January 8, 2025
概括
这项研究揭示了低密度聚乙烯 (LDPE) 和高密度聚乙烯 (HDPE) 中复杂的内部摩擦光谱. 在广泛的温度范围内观察到它们的光谱和强度特征的差异.
科学领域:
- 材料科学 材料科学 材料科学
- 聚合物物理 聚合物物理
- 固态物理 固态物理
背景情况:
- 内部摩擦和频率依赖的机械特性对于理解聚合物行为至关重要.
- 聚乙烯,其低密度 (LDPE) 和高密度 (HDPE) 形式,表现出不同的结构和机械特性.
研究的目的:
- 研究LDPE和HDPE振荡过程的内部摩擦光谱和温度依赖性.
- 分析剪切模量缺陷,内部摩擦机制和观察到的消散过程之间的关系.
- 为了比较LDPE和HDPE之间的机械和光谱差异.
主要方法:
- 对LDPE和HDPE从-150°C到+150°C的内部摩擦光谱和振荡频率进行实验测量.
- 剪切模量缺陷和内部摩擦机制的理论分析.
- 对强度特征和取决于温度的剪切模量变化进行比较分析.
主要成果:
- 内部摩擦光谱显示了多个具有不同强度的局部消散过程和复杂的,尖的,温度依赖的跳跃.
- 在 -50°C至+50°C范围内,在LDPE和HDPE之间观察到光谱结构的显著差异.
- 理论分析将异常频率变化与剪模缺陷联系起来,并确定了关键的内部摩擦机制.
结论:
- LDPE和HDPE具有不同的内部摩擦光谱和温度依赖的机械反应.
- 局部消耗损失显著影响聚乙烯的剪切模量和强度特征.
- 该研究提供了对不同聚乙烯结构中基本的机械减压机制的见解.
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