Perchlorate Leaching from Solid Rocket Motor Propellant in Water

Abstract

Several launch vehicle solid rocket motor propellants contain ammonium perchlorate as a major ingredient, and so the potential exists for perchlorate release to the environment during launch operations and propellant manufacture. Solid composite base propellants containing four types of binder were studied: hydroxyl-terminated polybutadiene, carboxyl-terminated polybutadiene, polybutadiene-acrylic acid-acrylonitrile terpolymer, and polyurethane. The rate of perchlorate release from solid propellant during immersion in deionized and simulated seawater has been measured at 5, 20, and 29°C. The rate-limiting step is most probably diffusion, and the diffusion coefficient is given. Arrhenius terms are presented to facilitate calculation of diffusion coefficients at intermediate temperatures. The diffusion coefficients for all propellant types and conditions tested fall in the range from 3.6 X 10 - 1 2 to 1.1 × 10 - 1 3 m 2 s - 1 . The diffusion coefficients for each propellant type are proportional to temperature and inversely related to salinity.