摘要
柔性器件使用过程中反复拉伸与折叠会改变封装材料微观结构,导致空气中的水等更容易进入器件内部,影响器件的性能和寿命。在微观层面理解拉伸过程中封装材料链构象变化和水蒸气阻隔性减弱机制有利于材料设计,从而改善封装材料的性能,延长柔性器件的使用寿命。目前,常规实验手段很难从微观层面上分析聚合物链构象的变化。本文选取12种聚合物柔性封装材料聚酰亚胺(PI),通过分子动力学模拟拉伸和拉伸过程中水蒸气阻隔性的衰减,探究杨氏模量、自由体积和PI链构象之间的关系,深入理解拉伸过程中水蒸气阻隔性发生衰减的机制,在以上基础上提出采用交联的方法改善拉伸过程中水阻隔性衰减的策略。以上结果对聚合物封装材料的分子设计具有参考价值。
The repeated stretching and folding of flexible devices during use can lead to changes in the microstructure of packaging materials,making it easier for water and oxygen from the air to enter the interior of the devices,thereby affecting their performance.Understanding the conformational changes of polymer chains in the packaging material at the microscopic level during the stretching process and the mechanism behind the weakening of water vapor barrier properties is beneficial for material design,which can help improve the performance of packaging materials and prolong the lifespan of flexible devices.Currently,conventional experimental methods face difficulties in analyzing the changes in polymer chain conformations at the microscopic level.In this study,12 types of polyimide(PI)polymer flexible packaging materials were selected.Molecular dynamics simulations were employed to investigate the attenuation of water vapor barrier properties during stretching and the relationship between Young’s modulus,free volume,and PI chain conformations.This approach deepens our understanding of the mechanism behind the degradation of water vapor barrier properties during the stretching process.Furthermore,based on this understanding,the molecular conformation mechanism for improving the attenuation of water barrier properties during stretching through cross-linking methods is explored.The obtained results provide valuable references for the molecular design of polymer packaging materials.
作者
韩立鑫
张涵
熊良涛
张建华
李浩源
HAN Li-xin;ZHANG Han;XIONG Liang-tao;ZHANG Jian-hua;LI Hao-yuan(School of Microelectronics,Shanghai University,Shanghai 201800,China)
出处
《高分子通报》
CAS
CSCD
北大核心
2024年第8期1061-1072,共12页
Polymer Bulletin
基金
国家重点研究发展计划(项目号2022YFB3603103)。
关键词
聚酰亚胺
水蒸气阻隔性
分子模拟
自由体积
链构象
Polyimide
Water vapor barrier properties
Molecular simulation
Free volume
Chain conformation
