Zeng Yi, Liu Yiwu, Tan Jinghua, Huang Jie, Liu Junjie, Tang Ao, Chen Chengliang, Chen Hong
State Key Laboratory for Powder Metallurgy, Centre South University, Changsha 410083, China.
National and Local Joint Engineering Center of Advanced Packaging Materials R & D Technology, Key Laboratory of Advanced Packaging Materials and Technology of Hunan Province, School of Packaging and Materials Engineering, Hunan University of Technology, Zhuzhou 412007, China.
Materials (Basel). 2021 Mar 13;14(6):1402. doi: 10.3390/ma14061402.
In order to meet the increasingly stringent requirements for heat resistance and barrier properties in the packaging and electronic device encapsulation field. A high-barrier polyimide (NAPPI) contains naphthalene ring and amide group was prepared by polymerization of a novel diamine (NAPDA) and pyromellitic dianhydride. The structure and properties of diamine monomers and polymers were characterized. Results show that the NAPPI exhibits superior barrier properties with extremely low water vapor and oxygen transmission rate values of 0.14 g·m·day and 0.04 cm·m·day, respectively. In addition, the NAPPI presents outstanding mechanical properties and thermal stability as well. This article attempts to explore the relationship between NAPPI structure and barrier properties by combining experiment and simulation. Studies on positron annihilation lifetime spectroscopy, Wide angle X-ray diffractograms and molecular dynamics simulations prove that the NAPPI has smaller interplanar spacing and higher chain regularity. In addition, the strong chain rigidity and interchain cohesion of NAPPI due to the presence of the rigid naphthalene ring and a large number of hydrogen bond interactions formed by amide groups result in compact chain packing and smaller free volume, which reduces the solubility and diffusibility of small molecules in the matrix. In general, the simulation results are consistent with the experimental results, which are important for understanding the barrier mechanism of NAPPI.
为了满足包装和电子器件封装领域对耐热性和阻隔性能日益严格的要求。通过新型二胺（NAPDA）与均苯四甲酸二酐聚合制备了一种含萘环和酰胺基的高阻隔聚酰亚胺（NAPPI）。对二胺单体和聚合物的结构与性能进行了表征。结果表明，NAPPI具有优异的阻隔性能，其水蒸气透过率和氧气透过率极低，分别为0.14 g·m·天和0.04 cm·m·天。此外，NAPPI还具有出色的机械性能和热稳定性。本文试图通过实验与模拟相结合的方式探究NAPPI结构与阻隔性能之间的关系。正电子湮没寿命谱、广角X射线衍射图谱和分子动力学模拟研究表明，NAPPI具有较小的面间距和较高的链规整度。此外，由于刚性萘环的存在以及酰胺基形成的大量氢键相互作用，NAPPI具有较强的链刚性和链间内聚力，导致链堆积紧密且自由体积较小，从而降低了小分子在基体中的溶解度和扩散率。总体而言，模拟结果与实验结果一致，这对于理解NAPPI的阻隔机理具有重要意义。
