Preparation method of high-elasticity and high-heat-resistance polyimide

The invention discloses a preparation method of high-elasticity and high-heat-resistance polyimide. The preparation method comprises the following steps: firstly, preparing cage-shaped octamer (gamma-aminopropyl) silsesquioxane by taking gamma-aminopropyl triethoxysilane as a raw material; then, completely dissolving cage-shaped octamer (gamma-aminopropyl) silsesquioxane and a polar solution in athree-neck bottle; sequentially adding diamine and dianhydride to obtain a yellow uniform viscous liquid, coating the liquid on a glass plate, putting the glass plate in a vacuum oven and a muffle furnace, taking out the glass plate, and sequentially carrying out constant-temperature water bath, cooling and demolding to finally obtain modified polyimide. The preparation method has the beneficial effects that the whole technological process is simple, the cost is reduced, important industrialization significance is achieved, and the modified polyimide has an excellent mechanical property and thermodynamic stability. 本发