With the development of downstream applications, functionalized polyimide (PI) composites have gradually become a research hotspot. The traditional approaches to prepare functional PI are complex and time-consuming, which are not suitable for large-scale production. In this paper, a three-step strategy for PI microspheres functionalization through PAA microsphere preparation, functional material cladding and thermal imidization is proposed. First, polyamide acid (PAA)-the precursor of polyimide, was prepared in the form of microspheres with a mean particle size of about 2 μm by water vapor induced phase separation (WVIPS) method. Subsequently, the functional fillers like TiO₂ and graphene oxide have been successfully coated on the surface of PAA microspheres by hydrogen bonding and electrostatic adsorption force, respectively. It is worthy to note that the coated microspheres exhibiting well stability after the thermal imidization process. This work provided a facile and efficient strategy for the fabrication of functionalized PI composites.

随着下游应用的发展，功能化聚酰亚胺（PI）复合材料逐渐成为研究热点。制备功能性PI的传统方法复杂且耗时，不适合大规模生产。本文提出了通过PAA微球制备，功能材料包覆和热酰亚胺化来实现PI微球功能化的三步策略。首先，通过水蒸气诱导相分离（WVIPS）方法，以平均粒径约为2μm的微球形式制备聚酰胺酸（PAA）-聚酰亚胺的前体。随后，功能性填料如TiO ₂氧化石墨烯和氧化石墨烯分别通过氢键和静电吸附力成功地涂覆在PAA微球表面。值得注意的是，在热酰亚胺化过程之后，涂覆的微球表现出良好的稳定性。这项工作为功能化PI复合材料的制造提供了一种简便有效的策略。