Polyimide nanocomposites based on functionalized graphene sheets: Morphologies,thermal properties,and electrical and thermal conductivities

Polyimide (PI) films were prepared by reacting 4,4′-(4,4′-isopropylidene-diphenoxy)-bis(phthalic anhydride) and 1,3-bis(4-aminophenoxy)benzene. The 4-phenylbutylamine-functionalized graphene sheets (PBA-GSs) used for the preparation of the PI nanocomposite films were prepared by mixing a dispersion of graphite oxide with a solution of the ammonium salt of 4-phenylbutylamine (PBA). PI nanocomposite films containing different amounts of PBA-GS (0–10 wt%) were compared in terms of their morphologies, thermal properties, and electrical and thermal conductivities. Only a small amount of PBA-GS was required to improve the thermal properties and thermal conductivities of the PI; the maximum enhancements in these parameters were observed at 1 and 3 wt% PBA-GS, respectively. In contrast, the electrical conductivity of the PI hybrid films continued to increase with increasing PBA-GS content from 1 to 10 wt%.