Preparation method of fiber polyimide composite material with improved high-temperature mechanical and heat-conducting properties

A preparation method of a fiber polyimide composite material with improved high-temperature mechanical and heat-conducting properties relates to the technical field of fiber composite materials, and comprises the following steps: preparing polyamide acid, preparing a nano-sheet polyamide acid solution, and preparing fiber nano-sheet polyamide acid aerogel to obtain the fiber polyimide composite material with improved high-temperature mechanical and heat-conducting properties. Finally, the fiber nanosheet polyamide acid gas is poured into polyimide resin under the vacuum condition, heating and curing are conducted, and the fiber polyimide composite material with the high-temperature mechanical performance and the heat-conducting performance is obtained. According to the method, the nanosheet polyamide acid aerogel is constructed between the fiber cloth through directional freeze drying for the first time, the heat conductivity of the fiber composite material in the thickness direction is improved, and the mech