A molecular theory design was carried out to synthesize a diamine monomer 1-(4-tert-butylphenyl)-1,1-bis[4-(4-aminophenoxy)] phenylethane containing tert-butyl, ether linkage, and triphenylmethane units. Then it was polymerized with several commercial aromatic dianhydrides, including diphenyl hexafluoroisopropylidene tetraic acid dianhydride (6FDA), diphenyl ether tetracarboxylic dianhydride (ODPA), biphenyltetracarboxylic dianhydride (BPDA), and benzophenone tetraacid dianhydride (BTDA), via the conventional two-step method to afford a series of aromatic polyimides (PIs). The structure and properties of the polymer were characterized by Fourier transform infrared (FTIR) spectroscopy, solubility test, thermogravimetric analysis, differential scanning calorimetry, ultraviolet–visible spectroscopy, and tensile tests. The results showed that there were characteristic peaks of PI around 1776, 1720, and 1378 cm−1 in the FTIR spectra; 6FDA-, ODPA-, and BPDA-based PI are easily soluble in N-methylpyrrolidone (NMP), concentrated sulfuric acid, N,N-dimethylacetamide (DMAc), pyridine, Tetrahydrofuran (THF), Trichloromethane (CHCl3), and other common organic solvents showing excellent solubility. In a nitrogen atmosphere, the glass transition temperature of the PI films are between 246°C and 275°C, the temperature of 5% weight loss is above 501°C, and the residual mass fraction at 750°C is 53–61%. The mechanical properties range from 67.2 MPa to 88.6 MPa. In addition to the BTDA-based PI film, the other three types of PI have good transparency. The simultaneous introduction of tert-butyl, ether linkages, and triphenylmethane units has a synergistic effect, which greatly improves the solubility of PI and maintains good thermal stability, mechanical properties, and optical properties of PI at the same time.

中文翻译：

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含有叔丁基、醚键和三苯基甲烷单元的可溶性聚酰亚胺的合成和性能

进行分子理论设计以合成含有叔丁基、醚键和三苯基甲烷单元的二胺单体1-(4-叔丁基苯基)-1,1-双[4-(4-氨基苯氧基)]苯基乙烷。然后与几种商品化的芳族二酐，包括二苯基六氟异亚丙基四酸二酐（6FDA）、二苯醚四羧酸二酐（ODPA）、联苯四羧酸二酐（BPDA）和二苯甲酮四酸二酐（BTDA），通过常规的两步法聚合得到提供一系列芳香族聚酰亚胺 (PI)。通过傅里叶变换红外（FTIR）光谱、溶解度试验、热重分析、差示扫描量热法、紫外-可见光谱和拉伸试验对聚合物的结构和性质进行了表征。结果表明，在FTIR光谱中，PI在1776、1720和1378 cm-1附近存在特征峰；6FDA-、ODPA-和BPDA-based PI 易溶于N-甲基吡咯烷酮(NMP)、浓硫酸、N,N-二甲基乙酰胺(DMAc)、吡啶、四氢呋喃(THF)、三氯甲烷(CHCl3) 和其他常见的有机溶剂表现出优异的溶解性。在氮气气氛中，PI薄膜的玻璃化转变温度在246-275°C之间，5%失重温度在501°C以上，750°C时的残余质量分数为53-61% . 机械性能范围为 67.2 MPa 至 88.6 MPa。除BTDA基PI薄膜外，其他三种PI薄膜均具有良好的透明性。同时引入叔丁基、醚键和三苯甲烷单元具有协同效应，