Enhanced thermal and mechanical properties of polyimide/graphene composites

Polyimide (PI)/graphene sheets (GSs) composites were prepared by solution blending. The incorporation of GSs into PI increased the thermal conductivity, thermal stability and mechanical properties of PI. The thermal conductivity of PI/GSs composites was significantly improved compared with that of neat PI from 0.254 to 1.002 W/mK; this can be attributed to the homogeneous dispersion of graphene and the formation of heat conduction pathway. Furthermore, the Young modulus of PI/GSs was raised up to 4.04 GPa, approximately two-fold enhancement in comparison with that of neat PI. In addition, the incorportation of GSs in PI indicated excellent optical transparency at the lowest weight fractions of GSs and modified wettability of PI films.