Exposure of Elastomers to Hydrazine and Air, Water Vapor, or Carbon Dioxide

摘要

Specimens of Stillman Rubber (SR) 721-P80 and SR 724-90 (forms of ethylene-propylene rubber) potential elastomers for valve seat applications in hydrazine monopropellant systems, were alternately exposed to hydrazine and either air, water vapor, or carbon dioxide. The weight changes of the elastomers were determined during these cyclic exposures, and periodic checks of the thickness changes were made. The weight change for SR 724 leveled off at 2 to 3 percent, while that of SR 721 continued to increase with the number of cycles (for hydrazine and vapor, 26 percent after 40 cycles). SR 724 is superior to SR 721 in terms of its swelling characteristic with hydrazine where periodic exposures to air are encountered. (Author)