高强高韧聚酰亚胺纤维的构筑及其形成机理研究

（限3000 characters）: . The development and improved quality of novel polyimide fibers is one of the important areas and topics in the development of modern chemical fiber industry. This research topic is to fabricate triaxial electrospun polyimide fibers with high strength and high toughness by triaxial electrospinning. The mechanical properties of triaxial electrospun polyimide fibers will be tuned by changing the arrangement, the amount and the thickness of the rigid and soft moieties in the fibers. The morphology and cohesion at the interface will be observed by Transmission Electron Microscopy and Scanning Electron Microscopy. The molecular cross-linking between the moieties will be studied by FT-IR spectroscopy. The molecular orientation of the moieties in the triaxial fibers will be quantitatively determined by polarized Raman spectroscopy. The mechanical properties of triaxial electrospun polyimide fibers will be measured by tensile tester and micro-tensile testing machine. The high quality polyimide fibers with strength > 2 GPa and toughness > 60 J/g simultaneously will be achieved through analyzing the formation mechanism and optimizing the processing parameters of the fibers. This project will provide new concept for the fabrication of high quality electrospun fibers in the future.

聚酰亚胺新型纤维的开发与品质提升是现代化纤行业发展的重点领域和课题之一。本项目通过三元同轴静电纺丝技术构筑具有三元同轴结构的高强高韧聚酰亚胺纤维。通过改变三元结构中刚性组分和柔性组分的排布，各组分在纤维中的含量，以及各层结构的厚度来调节三元同轴电纺聚酰亚胺的力学性能。通过透射电镜和扫描电镜观察各组分在界面处的形貌和粘结性；通过红外光谱研究聚酰亚胺分子在组分间的“分子间交联”；通过偏振拉曼光谱定量分析各组分在三元同轴电纺聚酰亚胺纤维中的取向度；通过力学拉伸仪和微纳米纤维张力仪研究三元同轴电纺聚酰亚胺纤维的力学性能。通过分析和归纳高强高韧三元同轴电纺聚酰亚胺纤维的形成机理，优化各项加工参数，有望达到聚酰亚胺纤维强度 > 2 GPa，韧性 > 60 J/g的目标，同时为今后制备具有优异性能的电纺纤维提供新的思路。

聚酰亚胺新型纤维的开发与品质提升是现代化纤行业发展的重点领域和课题之一，而同时具备高强高韧性能的聚酰亚胺纤维一直是纤维材料领域急需解决的难题之一。本项目通过三元同轴静电纺丝技术成功构筑了具有三元同轴结构的电纺聚酰亚胺纤维。通过改变三元结构中刚性组分和柔性组分的排布，各组分在纤维中的含量，以及各层结构的厚度可以进一步调节三元同轴电纺聚酰亚胺的的微观结构和力学性能。电镜结果显示各组分在界面处结合牢固，红外光谱显示不同组分的聚酰亚胺分子在界面处存在“分子间交联”，偏振拉盘光谱显示各组分在纤维中具有良好的取向度。力学性能测试结果显示，随着刚性组分含量的提升，聚酰亚胺纤维模量逐渐增加，断裂伸长率逐渐减小，强度和韧性呈现出先增加后减小的趋势。同时力学测试结果表明刚性组分和柔性组分在三元结构中交替排列均可以制备出同时兼具高强度和高韧性的电纺聚酰亚胺纤维。通过优化各项参数所制备的聚酰亚胺三元同轴纤维成功实现强度 > 2 GPa，韧性 > 60 J/g的目标。该项目的成功实施为今后制备具有优异力学性能的电纺纤维提供新的思路，有利于拓展电纺纤维在不同领域的应用。