A versatile strategy of preparing colored polyimide (PI) films is developed by embedding colored monomers on the backbones of colorless substrate polymers. Intrinsically colored PI films of four colors—red, yellow, blue, and purple—are prepared by introducing relative chromophores to the substrate PI that are synthesized from 2,2′-bis(trifluoromethyl)benzidine (TFMB) and 4,4′-(hexafluoroisopropylidene) diphthalic anhydride (6FDA)—two widely used monomers for colorless and transparent PI films. In addition, a series of orange and green PI films are prepared by simple mixing of the red, yellow, or blue PIs. The properties of these colored PI films are characterized, exhibiting good mechanical, thermal, and solubility properties, as well as different color and brightness depending on the amounts and types of chromophores. The optical properties of these films are determined by UV–vis spectroscopy and Commission Internationale de I'Eclairage (CIE) Lab. It is demonstrated that the introduction of even small amounts of chromophores can afford spectrally colored films while maintaining the original benign properties of the substrate PIs.

中文翻译：

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通过在聚合物主链上嵌入发色团制备本征色聚酰亚胺薄膜

通过将有色单体嵌入无色基材聚合物的主链上，开发了一种制备彩色聚酰亚胺（PI）薄膜的通用策略。通过将相关发色团引入由 2,2'-双（三氟甲基）联苯胺 (TFMB) 和 4,4'- （六氟异亚丙基）二邻苯二甲酸酐 (6FDA)——两种广泛用于无色透明 PI 薄膜的单体。此外，通过简单混合红色、黄色或蓝色PI，制备了一系列橙色和绿色PI薄膜。这些彩色 PI 薄膜的性能得到了表征，表现出良好的机械、热和溶解性能，以及根据发色团的数量和类型而不同的颜色和亮度。这些薄膜的光学特性由紫外可见光谱和国际照明委员会 (CIE) 实验室测定。事实证明，即使引入少量的发色团也可以提供光谱彩色薄膜，同时保持底物 PI 的原始良性特性。