This chemical is often used as the oxidizer in rocket propellant, when combined with a hydrazine based rocket fuel. Nitrogen tetroxide is a very strong oxidizer, and Kalrez 1045 is resistant to oxidizing liquids; it has been the product of choice for hypergolic propellant applications.
DuPont's Kalrez 7745® perfluoroelastomer parts is the suggested alternative to Kalrez® 1045, for use in nitrogen tetroxide applications. It has excellent resistance to aggressive oxidizing media and overall excellent chemical resistance. In addition, its mechanical properties make it suitable for use in static and dynamic applications.
Table 1 shows the comparison of physical properties between Kalrez® 1045 and Kalrez® 7745.
Table 2 compares these two products in nitrogen tetroxide immersion testing. The table shows comparison data after exposure periods of 70, 336 and 672 hours. DuPont™ Kalrez® 7745 exhibits lower volume swell, lower weight gain, and improved physical properties versus 1045, after long- term exposure to nitrogen tetroxide at 35°C.
For applications involving nitrogen tetroxide and Kalrez® perfluoroelastomer parts, please contact the Gallagher Engineering Department @ 1-800-822-4063 to review the specific application to determine proper seal selection and design.
Samples of DuPont™ Kalrez® 7745 are available for product testing. Note that parts made from this product grade may be export controlled.
Contact the Gallagher Fluid Seals engineering department to learn more about how these products can help your next project.