目前，能源领域不断发展，对电容器要求不断提高，兼具高温性能和高储能的电容器已成为研究热点。其中高储能密度即要求其具备高介电常数和低介电损耗。特种工程材料聚酰亚胺（PI）因其耐高温性能而备受人们青睐，但其较低储能密度制约其应用。为更好地利用聚酰亚胺的耐高温性能，从其合成原料的多样性出发，寻找优异合成路线，该研究以制备高介电常数与低介电损耗聚酰亚胺（PI），研究同分异构体2，3，3'，4'-联苯四甲酸二酐（a-BPDA）和3，3'，4，4'-联苯四酸二酐（s-BPDA）对聚酰亚胺介电性能的影响为目标，以a-BPDA、s-BPDA、3，3'，4，4'-二苯甲酮四酸二酐（BTDA）、4，4'-双（3-氨基苯氧基）二苯基砜（m-BAPS）为原料，通过三元共聚制备了PI薄膜，从而验证方案可行性。在此基础上调配原料比例，探究最佳性能时各种原料配比。并运用傅里叶红外光谱（FTIR）分析、X射线衍射（XRD）分析、热性能分析和介电性能分析对薄膜进行表征。实验结果表明：a-BPDA、s-BPDA、BTDA和m-BAPS可成功合成聚酰亚胺薄膜；合成的薄膜仍可以保持较高的热学性能，其中a-BPDA和s-BPDA分别将聚酰亚胺的玻璃化转变温度最高提升至245.8 ℃和239.1 ℃。s-BPDA与a-BPDA对聚酰亚胺的介电性能产生不同影响，当s-BPDA与BTDA物质的量比为3∶2时，在1 000 Hz下sPI介电常数为4.25，介电损耗为0.002 9，当a-BPDA与BTDA物质的量比为3∶2时，aPI介电常数为3.49，介电损耗为0.002 3；综合对比下，s-BPDA对于聚酰亚胺的热学性能和介电性能改善效果更加明显。

At present, with the development of the energy field, the requirements for capacitors continue to increase. Capacitors with high temperature performance and high energy storage have become a research hotspot. High energy storage density requires high dielectric constant and low dielectric loss. The special engineering material polyimide (PI) is favored by people because of its high temperature resistance, but its low energy storage density restricts its application. In order to make better use of the high temperature resistance of polyimide and find an excellent synthesis route from the diversity of its synthetic raw materials, this paper aimed to prepare polyimide (PI) with high dielectric constant and low dielectric loss, and study the effect of isomer 2,3,3',4'-biphenyltetracarboxylic dianhydride (a-BPDA) and 3,3',4,4'-biphenyltetracarboxylic dianhydride (s-BPDA) on the dielectric properties of polyimide. Using a-BPDA, s-BPDA, 3,3',4,4'-benzophenonetetracarboxylic dianhydride (BTDA), 4'-bis (3-aminophenoxy) diphenyl sulfone (m-BAPS) as raw material, PI film was prepared by ternary copolymerization, so as to verify the feasibility of the scheme. On this basis, the proportion of raw materials was allocated to explore the best performance of various raw material ratios. The films were characterized by FTIR analysis, XRD analysis, thermal performance analysis and dielectric performance analysis. The experimental results show that a-BPDA, s-BPDA, BTDA and m-BAPS can successfully synthesize polyimide films. The synthesized films still have high thermal properties. a-BPDA and s-BPDA increase the glass transition temperature of polyimide to 245.8 ℃ and 239.1 ℃, respectively. s-BPDA and a-BPDA have different effects on the dielectric properties of polyimide. When the ratio of s-BPDA to BTDA is 3∶2, the dielectric constant of sPI was 4.25 and the dielectric loss is 0.002 9 at 1 000 Hz. When the ratio of a-BPDA to BTDA is 3∶2, the dielectric constant of aPI is 3.49 and the dielectric loss is 0.002 3. Under comprehensive comparison, s-BPDA is more effective in improving the thermal and dielectric properties of polyimide.