The invention discloses a preparation method of a
coal ash modified nanometer aluminum
oxide /
polyimide composite film. The preparation method can be used for preparing the nanometer aluminum
oxide hybrid polyimide film by utilizing nanometer aluminum
oxide sol, so that
corona-resistant characteristics and
dielectric performances of the
polyimide film can be remarkably improved, and the
corona-resistant service life of the nanometer aluminum oxide
hybrid polyimide film is 8-9 times that of the pure polyimide film. The preparation method further can be used for improving and overcoming the defects of the pure polyimide film, remarkably improving the
mechanical strength, the
hardness, the abrasion performance and
thermal decomposition temperature of the pure polyimide film, so that the comprehensive performances of the pure polyimide film are improved. Moreover, the novel polyimide nanometer
composite film prepared by the preparation method disclosed by the invention has the characteristics of being high
temperature resistance, good in mechanical performances, excellent in electrical performances, easy to
machine and form, low in cost and the like, so that the development requirements of high and new technologies including the
aerospace technology, the micro-
electronics technology, the electrical technology, the
chemical technology, the
energy technology and the like can be completely satisfied.