Developing Meta-aramid materials that combine flexibility and strength will greatly expand their application fields. In previous work, it was demonstrated that aromatic ether bonds can contribute to improving flexibility. In addition, micro-branched chain structures can reduce intermolecular forces by increasing fractional free volume, while newly formed hydrogen bonding can maintain polymer strength. Therefore, two flexible polymers were obtained by incorporating 4,4′-diaminodiphenyl ether (ODA) and 4,4′-oxybis [3-(trifluoromethyl)benzenamine] (OTB) to the molecular chains, respectively, and flexible films were prepared by a combination of solution casting and dry-wet processing methods. By studying the properties of copolymer films with 10% ODA and 10% OTB added, it was found that they can maintain thermal stability and mechanical strength while improving the flexibility of the films. The AFM results visually showed that the DMT modulus of the modified films decreased at the micro level and DMA indicated that the introduction of ODA and OTB can shorten the molecular relaxation time, which reflected the improvement of molecular chain flexibility. Through molecular dynamics simulations, the differences were compared in molecular chain conformation, mean square displacement and hydrogen bonding after the introduction of ODA and OTB and the combined mechanism of aromatic ether bonds and CF side groups was confirmed in improving flexibility and maintaining mechanical strength.

中文翻译：

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兼具柔韧与强度的间位芳纶薄膜：芳香醚键与微支化结构的共同作用

开发兼具柔韧性和强度的间位芳纶材料将大大拓展其应用领域。在之前的工作中，已经证明芳香醚键有助于提高灵活性。此外，微支链结构可以通过增加自由体积分数来减少分子间力，而新形成的氢键可以保持聚合物强度。因此，通过分别将4,4'-二氨基二苯醚(ODA)和4,4'-氧双[3-(三氟甲基)苯胺](OTB)结合到分子链上获得了两种柔性聚合物，并通过以下方法制备了柔性薄膜溶液浇铸和干湿法加工方法的结合。通过研究添加10%ODA和10%OTB的共聚物薄膜的性能，发现它们可以保持热稳定性和机械强度，同时提高薄膜的柔韧性。 AFM结果直观地表明，改性薄膜的DMT模量在微观层面有所下降，DMA表明ODA和OTB的引入可以缩短分子弛豫时间，体现了分子链柔韧性的提高。通过分子动力学模拟，比较了引入ODA和OTB后分子链构象、均方位移和氢键的差异，证实了芳香醚键和CF侧基的组合机制在提高柔韧性和保持机械强度方面的作用。