New Synthetic Approach of Fluorine-Containing Graphene Oxide for Improving Dielectric and Mechanical Properties of Polyimide Composites

A new approach to synthesize fluorine-containing graphene oxide (FCGO) was proposed, in which a less toxic reagent was used rather than fluorine gas or anhydrous hydrogen fluoride. The dielectric and mechanical properties of polyimide composites were improved by incorporating a small amount of FCGO. FCGO served as not only nanofiller to lower the dielectric constant of PI films but also inorganic toughening particles to improve the toughness of PI films. The dielectric constant of PI films with 0.6 wt % FCGO was decreased from 3.33 for pure PI to 2.34. In addition, both the tensile strength and Young’s modulus of PI films with 0.6 wt % FCGO were increased to 141 MPa and 4.95 GPa from 118 MPa and 2.81 GPa for pure PI, respectively. In addition, its tensile energy to break was enhanced to 31.6 MJ/m³ from 20.8 MJ/m<sup>3