Abstract: Firstly,graphene and barium strontium titanate powder modified with silane coupling agent was prepared.The graphene/BST/PVDF composite thin films were prepared by solution mixing method.The microstructure of the composite film,dielectric properties and thermal stability were measured and analyzed.The results show that silane coupling agent is successfully grafted onto the surface of graphene and barium titanate powder.They can be better dispersed in the PVDF matrix,the addition of graphene can significantly improve the dielectric properties of the material.When the mass fraction of graphene is 4.06;,the dielectric constant of the composite thin film has reached 515,and the dielectric loss is 0.6.In the seepage occur when mass fraction of 4.14;,dielectric constant of 1500 and dielectric loss reach 5 or so.The increase of the dielectric properties of the composites is greatly improved by the addition of graphene,and composite materials have good temperature stability in the common temperature range.

Key words: Firstly,graphene and barium strontium titanate powder modified with silane coupling agent was prepared.The graphene/BST/PVDF composite thin films were prepared by solution mixing method.The microstructure of the composite film,dielectric properties and thermal stability were measured and analyzed.The results show that silane coupling agent is successfully grafted onto the surface of graphene and barium titanate powder.They can be better dispersed in the PVDF matrix,the addition of graphene can significantly improve the dielectric properties of the material.When the mass fraction of graphene is 4.06;,the dielectric constant of the composite thin film has reached 515,and the dielectric loss is 0.6.In the seepage occur when mass fraction of 4.14;,dielectric constant of 1500 and dielectric loss reach 5 or so.The increase of the dielectric properties of the composites is greatly improved by the addition of graphene,and composite materials have good temperature stability in the common temperature range.