Xu Wenhao, He Xiaojie, Zhou Yu, Jiang Lan, Yang Weiyou, Lu Qinghua, Xiao Peng
Institute of Micro/Nano Materials and Devices, Ningbo University of Technology, Ningbo 315211, China.
School of Chemical Science and Engineering, Tongji University, Siping Road No. 1239, Shanghai 200092, China.
Polymers (Basel). 2025 May 28;17(11):1505. doi: 10.3390/polym17111505.
Fluorinated polyimide (FPI), renowned for its exceptional low-dielectric properties, colorless transparency, high-temperature resistance, and flexibility, has emerged as an ideal material for addressing challenges in 5G/6G high-frequency signal transmission and flexible electronic substrates. Nevertheless, the structure-property relationship between molecular architectures and the dielectric characteristics of FPI films remains insufficiently understood, necessitating urgent elucidation of the underlying mechanisms. In this study, a diamine monomer containing bis-amide bonds, 4-amino-N-{4-[(4-aminobenzoyl)amino]phenyl}benzamide (PABA), was synthesized. Subsequently, six FPI films (FPAIs, FPEIs, and FPEsIs) with distinct structural features were prepared through homopolymerization of PABA and five other diamines (containing amide bonds, ether, and ester groups) with fluorinated dianhydride (6FDA). Systematic characterization of thermal, mechanical, optical, and dielectric properties revealed that these films exhibit excellent thermal stability (: 296-388 °C), mechanical strength (: 152.5-248.1 MPa, : 2.1-3.4 GPa), and optical transparency (: 82-86%). Notably, they demonstrated a low dielectric constant ( as low as 2.8) and dielectric loss ( down to 0.002) under both low- and high-frequency electric fields. Furthermore, molecular dynamics simulations and quantum chemical were employed to calculate critical physical parameters and HOMO-LUMO energy levels of the six FPIs. This computational analysis provides deeper insights into the structure-performance correlations governing dielectric behavior and optical transparency in FPIs. The findings establish valuable theoretical guidance for designing advanced PI films with tailored dielectric properties and high transparency.
氟化聚酰亚胺（FPI）以其出色的低介电性能、无色透明性、耐高温性和柔韧性而闻名，已成为解决5G/6G高频信号传输和柔性电子基板挑战的理想材料。然而，FPI薄膜的分子结构与介电特性之间的结构-性能关系仍未得到充分理解，迫切需要阐明其潜在机制。在本研究中，合成了一种含双酰胺键的二胺单体，即4-氨基-N-{4-[(4-氨基苯甲酰基)氨基]苯基}苯甲酰胺（PABA）。随后，通过PABA与其他五种二胺（含酰胺键、醚键和酯基）与氟化二酐（6FDA）进行均聚反应，制备了六种具有不同结构特征的FPI薄膜（FPAIs、FPEIs和FPEsIs）。对热、机械、光学和介电性能的系统表征表明，这些薄膜具有出色的热稳定性（：296-388℃）、机械强度（：152.5-248.1MPa，：2.1-3.4GPa）和光学透明度（：82-86%）。值得注意的是，它们在低频和高频电场下均表现出低介电常数（低至2.8）和介电损耗（低至0.002）。此外，采用分子动力学模拟和量子化学方法计算了六种FPI的关键物理参数和HOMO-LUMO能级。这种计算分析为深入了解FPI中控制介电行为和光学透明度的结构-性能相关性提供了更深入的见解。这些发现为设计具有定制介电性能和高透明度的先进PI薄膜提供了有价值的理论指导。
