피리딘 염으로 기능화된 그래핀 나노 시트를 이용한 기계적으로 강한 폴리이미드 나노복합체 개발

Abstract

Polyimide (PI) nanocomposites with outstanding thermal stability, mechanical properties and excellent electrical performance are used in various industries such as aerospace engineering, capacitors, adhesives and flexible photoelectric devices. With the increasing demand for PI nanocomposites, high-performance PI nanocomposites were prepared by mixing many organic/inorganic fillers in the PI matrix to expand the application of PI. In this study, we report the fabrication of high-performance PI nanocomposite introducing functionalized reduced graphene oxide as a filler to the PI nanocomposite. To prevent graphene aggregation, the graphene surface was functionalized with pyridinium salt monomer to obtain I-rGO, and then PF6-rGO was synthesized through anion exchange. FT-IR, Raman, and XRD confirmed the successful surface modification and reduction of GO. TGA analysis showed improved thermal properties due to the large ion size and hydrophobicity of PF6-. A high-performance PI nanocomposite using functionalized reduced graphene oxide as a filler was prepared via in-situ polymerization and thermal imidization. 1 wt% PI/PF6-rGO increased tensile strength by 114.8 % (97.8 MPa) and Young's modulus by 117.3 % (2.78 GPa) compared to PI. The improved mechanical properties of the PI nanocomposite are attributed to the homogeneous dispersion of the functionalized rGO and the strong interaction between the PI matrix and the filler.