| abstract |
A multilayer composite film and its preparation method and application. The preparation method includes: respectively preparing a polyamic acid solution Ia, a polyamic acid solution Ib containing surface-modified inorganic nanoparticles, and a mixed solution Ic containing inorganic nanoparticles and multifunctional monomers; then mixing Ia, Ib and Ic At least two of these are alternately filmed and imidized, and the resulting multilayer composite film includes first and second outermost layers, and optionally an intermediate layer sandwiched therebetween, the first and second outermost layers. The two outermost layers are the polyimide layer PI-a formed by Ia or the polyimide layer PI-c formed by Ic, and the middle layer comprises a layer selected from the group consisting of PI-a, PI-b and PI-c A first intermediate layer of a kind of and optionally a second intermediate layer selected from at least one of PI-a, PI-b and PI-c alternately stacked with the first intermediate layer. The obtained multilayer composite film has high thermal conductivity, corona resistance and mechanical properties. |