▎ 摘　　要

This study proposes an effective approach using in situ polymerization, to fabricate large-area graphene oxide (GO)/polyimide (PI) composite films with outstanding mechanical properties. The GO/PI composite films provide ultrahigh tensile strength (up to 844 MPa) and Young's modulus (20.5 GPa). The NH2-functionalized GO (ODA-GO) is a versatile starting platform for polymer grafting, promoting excellent dispersion of GO within the polymer matrix, and forming strong links with the polymer to facilitate load transfer. The Young's modulus of the integrated GO-PI composite films with 3.0 wt% ODA-GO loading is 15 times greater, and the tensile strength is 9 times greater than comparable properties of pure PI film. The dielectric constant decreases with increasing GO content and a dielectric constant (D-k) of 2.0 was achieved. This approach provides a strategy for developing ultrahigh performance GO-polymer composite materials.