石墨烯增强新型含嘧啶环、吡啶环聚酰亚胺纳米纤维的制备与性能研究

Electrospun nanofibers are a class of representative high-performance nanomaterials which have attracted much attention in the worldwide field in recent years. In this item, we will design and synthesize a novel poly(amic acid) (PAA) with high molecular weight which contains pyridine and pyrimidine ring structures. Molecular level dispersion of high-quality graphene oxide (GO) nanosheets within novel PAA hosts could be fabricated while enhancing the interfacial interactions and improving the compatibility of different interfaces. Polyimide nanocomposite fibers which use graphene nanosheets as ideal reinforcing fillers are obtained by employing electrospinning technique and thermal imidization, of which the diameter reaches 50- - 300nm, the length is meter grade and the graphene nanosheets is well orientated along the fiber axis. With adjusting the interactions and synergies among the nanostructural units in the assembly process, the space controllability will be achieved. The relationship between macro-materials and cell assembly structure, shape and edge effects will be revealed. So the excellent performance of the graphene nanosheets and the rigid polyimide chains will be fully reflected in the macroscopic assembly structures. Establishing the nanocomposite technology of graphene and polyimide will be helpful to achieve the effective compounding in nanoscale. The research will provide an academic basis which could promote the industrialization development of polyimide fiber and offer excellent materials for national defense, aerospace areas and civil industry.

电纺聚合物纳米纤维是近年来在世界范围内吸引了广泛兴趣的纳米材料。本项目拟设计并合成分子主链含有嘧啶环、吡啶环等刚性基团高分子量聚酰胺酸，并将其与高质量氧化石墨烯进行纳米复合，通过增强界面间的相互作用和改善界面的相容性来实现异质分子间的均匀分散。利用静电纺丝技术、热亚胺化等手段构筑直径在50- - 300nm、长度达米级、分子取向性良好的石墨烯增强聚酰亚胺纳米纤维。调控纳米结构单元间相互作用以及组装过程中的协同效应，实现纳米组装结构的空间可控性，揭示宏观材料与组装单元结构、形状以及边缘效应之间的关系，使石墨烯、刚性聚酰亚胺链的优异性能跨越纳米尺寸，充分地体现在以其组装成的宏观结构之中。建立石墨烯与聚酰亚胺等高分子材料的纳米复合技术，实现材料在纳米尺度的有效复合。研究成果将为促进工业化的聚酰亚胺纤维发展提供科学依据，为国防科技、航天事业及民用工业提供卓越新材料。

对于聚合物基纳米复合材料，纳米填料在基体中的均匀分散至关重要。通过对纳米填料进行改性，可提高基体与填料之间的相容性，增加其界面相互作用对获得具有高性能及多功能的高分子纳米复合材料具有重要意义。本项目系统的研究了氧化石墨烯（GO），石墨烯，功能化石墨烯，新型聚酰亚胺的可控制备及其影响因素，解决了石墨烯在有机溶剂和聚合物中的分散性，稳定性这一关键科学问题。并通过增强界面间的相互作用和改善界面的相容性来实现异质分子间的均匀分散。成功的构筑石墨烯增强聚酰亚胺膜材料，结果表明：复合膜材料的力学性能，耐热性能，导电（导热）性能比纯聚酰亚胺膜有明显提高。另外，利用静电纺丝技术、热亚胺化等手段构筑直径在50--300nm、石墨烯沿纤维轴向取向的石墨烯增强聚酰亚胺纳米纤维。通过调控纳米结构单元间相互作用以及组装过程中的协同效应，实现纳米组装结构的空间可控性，揭示宏观材料与组装单元结构、形状以及边缘效应之间的关系，使石墨烯、刚性聚酰亚胺链的优异性能跨越纳米尺寸，充分地体现在以其组装成的宏观结构之中。建立石墨烯与聚酰亚胺等高分子材料的纳米复合技术，实现材料在纳米尺度的有效复合。取得了预期研究结果，达到预期研究目标。