Facile Fabrication of Polyimide-alumina Composite Coatings by Liquid Flame Spray

Polyimide is type of heterocyclic polymer compound characterized by an imide ring structure. The aromatic ring structure in polyimide facilitates good electrical properties, mechanical properties, thermal properties and radiation resistance, etc. It is widely used in the aerospace field, in electronic components and in the semiconductor industry. Traditional methods for the preparation of polyimide films have different limitations. Here, a new one-step method was established to prepare polyimide coatings using liquid flame spray. The effect of different mass fraction on the surface and cross section structure characteristics of polyimide coatings was studied. The formation process of the polyimide-alumina composite coatings was analyzed using single particles and coatings with different amount of alumina. The composite coating shows a flat and dense structure and excellent dielectric properties. The results shed light on construction of polymer-inorganic composite layers for widespread applications.