▎ 摘　　要

In this study, we have developed a facile and effective method for fabricating polyimide (PI)-based nanocomposites incorporating octadecylamine (ODA)-functionalized graphene oxide (ODA-fGO) nanosheets. ODA-fGO sheets exhibit superior dispersibility and compatibility with the PI matrix and are successfully obtained through a chemical reaction between graphene oxide (GO) and ODA. The PI-based composites of various loading content of ODA-fGO sheets were prepared via in situ polymerization and thermal imidization process. The mechanical and electrical properties of the PI/ODA-fGO composites were significantly improved relative to pure PI because of the excellent dispersion of ODA-fGO and the adequate compatibility between fillers and the PI matrix. A 40.7% increase in tensile strength and a 95.5% improvement of Young's modulus were observed for the 3 wt% ODA-fGO (PI/3 wt% ODA-fGO) loading content composite. The electrical and thermal conductivity of PI/3 wt% ODA-fGO was 3.8 x 10(-2) S m(-1) and 0.468 W m(-1) K-1, respectively, which is more than 10(11) times and almost 3 times higher than that of pure PI. The reported approach provides an effective strategy for developing high-performance and multifunctional polymer-based composite materials.