Atmospheric aging resistance: radiation resistance and low permeability: long-term exposure to the atmosphere, the surface and performance remain unchanged. Non-combustibility: The oxygen limit index is below 90. Acid and alkali resistance: insoluble in strong acids, strong alkalis and organic solvents. Oxidation resistance: resistant to corrosion by strong oxidants. Medium working temperature: -100℃~-250℃, medium working pressure: positive pressure: 2.5MPa, withstand negative pressure 70KPa at normal temperature.