在拉伸诱导结晶过程中,聚乙烯的板状方位分析和机械性能
Mohammed Althaf Hussain1, Takeshi Aoyagi2, Takeshi Kikutani3
1Faculty of Engineering, Fukuoka University, Fukuoka 814-0180, Japan.
Polymers
|June 13, 2025
概括
在高密度聚乙烯 (HDPE) 薄膜中的拉伸诱导结晶 (SIC) 产生了具有对齐链的强大,弹性材料. 这项分子动力学研究揭示了链条折叠和叶片对齐如何增强纤维状结构的机械性能.
科学领域:
- 材料科学 材料科学 材料科学
- 聚合物科学 聚合物科学
- 计算材料科学科学 计算材料科学
背景情况:
- 通过取决于方向的方法生产的聚乙烯薄膜具有增强的强度,弹性和降低的透性.
- 了解拉伸诱导结晶 (SIC) 背后的分子机制对于优化聚合物特性至关重要.
- 高密度聚乙烯 (HDPE) 是需要高机械性能应用的关键材料.
研究的目的:
- 通过分子动力学研究HDPE中SIC过程中链折叠和状晶体轴对齐的出现.
- 为了将形态变化与机械性能和结构参数相关联.
- 模拟类似纤维的聚乙烯薄膜的内部结构.
主要方法:
- 用分子动力学模拟来建模HDPE中的SIC过程.
- 监测的关键参数包括总密度 (ρ),结晶度 (%χc),每个链中的纠 (
),弹性模量和叶片链倾斜角 (θ). - 使用原始路径分析来评估链条纠的演变.
主要成果:
- 在拉伸 (~40%) 和放松 (~50%),伴随密度变化 (0.85至0.90g·cm−3) 的过程中,观察到晶度 (%χc) 的逐渐增加.
- 在拉伸和放松过程中,每条链平均纠数 (
) 减少,这表明结构重组. - 模拟的弹性模量 (~350-400 MPa) 和叶片链倾斜角度 (~20-35°) 与实验观测结果一致,证实了链条的显著对齐.
结论:
- SIC是一种有效的方法,用于创建具有高刚性,抗拉强度和降低透性的HDPE结构,模仿纤维形态.
- 该研究表明了分子层面的变化 (链条折叠,对齐) 和宏观材料特性之间的关系.
- 结果为设计具有定制纤维状结构的先进聚合物材料和复合材料提供了洞察力.
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