Enhanced thermal conductivity and dimensional stability of flexible polyimide nanocomposite film by addition of functionalized graphene oxide

Polyimide ( PI ) nanocomposites with both enhanced thermal conductivity and dimensional stability were achieved by incorporating glycidyl methacrylate‐grafted graphene oxide (g‐ GO ) in the PI matrix. The PI /g‐ GO nanocomposites exhibited linear enhancement in thermal conductivity when the amount of incorporated g‐ GO was less than 10 wt%. With the addition of 10 wt% of g‐ GO to PI ( PI /g‐ GO ‐10), the thermal conductivity increased to 0.81 W m −1 K −1 compared to 0.13 W m −1 K −1 for pure PI . Moreover, the PI /g‐ GO ‐10 composite exhibited a low coefficient of thermal expansion ( CTE ) of 29 ppm °C −1 . The values of CTE and thermal conductivity continuously decreased and increased, respectively, as the g‐ GO content increased to 20 wt%. Combined with excellent thermal stability and high mechanical strength, the highly thermally conducting PI /g‐ GO ‐10 nanocomposite is a potential substrate material for modern flexible printed circuits requiring efficient heat transfer capability.