Abstract Novel triphenylmethane-based polyimides and copolyimides were synthesized by polycondensation reaction of 4,4′-(4,4′-isopropylidenediphenoxy)bis(phthalic anhydride) with a triphenylmethane-based diamine, or an equimolar mixture of 4,4′-oxydianiline and triphenylmethane-based diamine, via conventional two-step procedure. Three novel diamines were developed as well, being obtained from ortho-toluidine and one of the following aldehydes: benzaldehyde, 4-bromobenzaldehyde or 4-fluorobenzaldehyde. The relationship between the macromolecular structural motif and physical properties of the synthesized polymers was investigated in detail, with emphasis on thermal transitions and stability, dielectric behavior, molecular disorder, mechanical toughness and gas separation performance. The amorphous, free-standing, tough and defectless films prepared from these polymers showed excellent thermal stability, their decomposition starting above 425 °C. For all polymer films which were subjected to dielectric properties measurements, the variation of the real and imaginary parts of the dielectric permittivity with frequency and temperature was measured and discussed. The values of the dielectric constant and dielectric loss were measured at room temperature and in the frequency domain from 1 Hz to 1 MHz, and the obtained results proved the beneficial effect of fluoro and bromo graphting on the dielectric constant reduction. The dielectric spectroscopy data showed distinct γ and β subglass transitions at lower activation energies for copolyimides compared to polyimides, suggesting that the incorporation of the co-monomer diamino-diphenyl ether allows faster motions of the small molecules, but hinders the mobility of charge carriers. The permeability of several gases through these membrane-forming materials were measured and discussed with respect to the structural variations in the polymer repeating unit.

中文翻译：

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结构 - 促进三苯甲烷的高性能 - 包含聚酰亚胺和共聚酰亚胺

摘要 通过 4,4'-(4,4'-异亚丙基二苯氧基)双（邻苯二甲酸酐）与三苯基甲烷基二胺或 4,4'-氧化二苯胺的等摩尔混合物的缩聚反应合成了新型三苯基甲烷基聚酰亚胺和共聚酰亚胺。和三苯甲烷基二胺，通过常规的两步程序。还开发了三种新型二胺，它们是从邻甲苯胺和以下醛之一获得的：苯甲醛、4-溴苯甲醛或 4-氟苯甲醛。详细研究了大分子结构基序与合成聚合物物理性质之间的关系，重点是热转变和稳定性、介电行为、分子无序、机械韧性和气体分离性能。无定形的、独立的、由这些聚合物制备的坚韧无缺陷的薄膜显示出优异的热稳定性，它们在 425°C 以上开始分解。对于进行介电特性测量的所有聚合物薄膜，测量并讨论了介电常数的实部和虚部随频率和温度的变化。在室温和 1 Hz 至 1 MHz 的频域中测量介电常数和介电损耗的值，所得结果证明了氟和溴绘图对介电常数降低的有益影响。介电光谱数据显示，与聚酰亚胺相比，共聚酰亚胺在较低的活化能下有明显的 γ 和 β 亚玻璃化转变，表明共聚单体二氨基-二苯醚的掺入允许小分子的更快运动，但阻碍了电荷载流子的移动性。测量了几种气体通过这些成膜材料的渗透性，并就聚合物重复单元的结构变化进行了讨论。