High - temperature resistant adhesives refer to a type of adhesives that can still maintain their original bonding performance when used at temperatures ranging from 200 to 500°C or even higher. These adhesives are mainly silicon (or boron) - containing polymers, aromatic heterocyclic high - temperature resistant polymers, and inorganic adhesives, etc.
PI adhesive is the earliest developed, most widely used, and has the best comprehensive performance among high - temperature resistant structural adhesives. After curing at 300°C, it has good heat resistance and shear strength under the condition of 300 - 400°C. It can be used for a long time at 230°C and can withstand a high temperature of 555°C for a short time. It also has the advantages of good low - temperature resistance, solvent resistance, wear resistance, flame retardancy, and an extremely low coefficient of thermal expansion, etc.