▎ 摘 要
Polyimide-graphene composites (PIG) were prepared with variable amounts of graphene, and their thermal properties were analyzed in films on substrates or sheet states. The thermal conductivities of PIG composite sheets gradually moved upwards with increase of graphene loading. Coefficient of thermal expansion of composite sheet was higher in out-of-plane mode than in-plane mode. The residual stress of a composite film was monotonously changed in accordance with the variation of temperature and lowered with increase of graphene. In addition, the residual stress of a composite film reached to the initial stress value during cooling process after heating. The stress profiles on further heating and cooling runs closely followed the stress profile during the first cooing run.