【摘要】 聚酰亚胺（PI）膜作为柔性显示基板的关键材料之一，其热性能和拉伸性能存在此消彼长的问题。基于此，本文以均苯四甲酸二酐（PMDA）、4,4′-二氨基二苯醚（ODA）和含杂环结构的4-氨基苯-2,5-吡啶二胺（PIDA）为原料，通过三元共聚与单体比例调控策略，制备了一系列PI膜，以优化其综合性能。研究了PI膜的化学结构、聚集态结构、热性能及拉伸性能。结果显示，PIDA单体的引入可显著降低PI膜的热膨胀系数（CTE）,提高弹性模量与玻璃化转变温度（T_g）。随着PIDA物质的量在PIDA与ODA总物质的量中的占比从0%增加到60%,PI膜的5%热分解温度(T_5%)在521～548℃范围；T_g从447℃提升至500℃以上；CTE从7.21×10^-5 K^-1降低至2.75×10^-5 K^-1。此外，PI膜的断裂伸长率和拉伸强度分别控制在2.4%～26.9%和42～119 MPa范围内。当PIDA物质的量为PIDA与ODA总物质的量的40%时，PI-40%膜展现出最优的综合性能(T_g=470℃,CTE=3.86×10^-5 K^-1,T_5%=529℃,断裂伸长率=10.1%,拉伸强度=108 MPa,弹性模量=1.8 GPa),说明其具有最佳应用潜力。本文不仅通过调节二胺比例，实现对PI膜性能调控，同时亦为柔性显示基板材料的开发提供了理论依据与实验方案。更多还原

【Abstract】 The polyimide（PI）film as one of the key materials of flexible display substrate, which has a trade-off effect between thermal and mechanical properties.Based on this, a series of PI films were prepared by terpolymerization and monomer ratio regulation strategy using pyromellitic dianhydride（PMDA）,4,4′-diaminodiphenyl ether（ODA）and 4-amino-benzene-2,5-pyridinediamine（PIDA）contains heterocyclic structure as raw materials for optimizing their comprehensive properties.The chemical structures, aggregation structures, thermal properties and tensile properties of PI films were investigated.The results show that the introduction of PIDA monomer significantly reduces the coefficient of thermal expansion（CTE）and increases the elastic modulus and glass transition temperature（T_g）of PI film.As the molar proportion of PIDA in the total molar amount of PIDA and ODA increases from 0% to 60%,the 5% thermal decomposition temperature(T_5%)is in the range of 521～548 ℃,T_g increases from 447 ℃ to more than 500 ℃,and CTE decreases from 7.21×10^-5 K^-1 to 2.75×10^-5 K^-1.In addition, the elongations at break and tensile strengths of PI films are controlled in 2.4%～26.9% and 42～119 MPa, respectively.When the molar amount of PIDA is 40% of the total molar amount of PIDA and ODA,PI-40% film shows the excellent comprehensive properties(T_g=470 ℃,CTE=3.86×10^-5 K^-1,T_5%=529 ℃,elongation at break=10.1%,tensile strength=108 MPa, elastic modulus=1.8 GPa),indicating a promising application prospect.This paper not only realized the regulation of PI film performances by adjusting the ratio of diamine but also provided theoretical basis and experimental scheme for the developments of substrate materials for flexible display.更多还原