ABSTRACT
Thermophysical properties of munitions compounds are required for understanding thermal, physical, and chemical parameters and mechanisms that govern the environmental fate and transport of the materials. Accurate experimental data on these properties are useful for the development of validated predictive models of the properties for designing munitions manufacturing processes, conducting life-cycle environmental analysis, and to develop cost-effective treatment processes for their environmental remediation. New insensitive munition (IM) formulations that are more stable and safe to handle are being developed by the U.S. Department of Defense (DoD). By design, these munitions are expected to be less sensitive to thermal pressure or electrical shocks and are less prone to premature ignition or explosion. At the same time, these munitions are expected to have high-energy density and meet several performance standards such as detonation velocity. These new munitions will be incorporated into the DoD inventory unless a waiver is granted, and will be packed at current Load, Assemble, and Pack (LAP) plants. Wastewaters from production and LAP facilities, and ground and surface water bodies near the training areas, will be contaminated with the IM compounds. Thus, the study of IM’s environmental fate and transport is an important aspect of the DoD’s environmental stewardship. Physical properties play an important role in studying IM’s environmental fate and transport. The fate and distribution of an IM compound released into the environment are primarily controlled by (1) prevailing environmental conditions such as temperature, pH, salinity, the presence of other hydrophilic and hydrophobic materials at the points of discharge, and (2) the physicochemical properties of the compound. Thus, accurate information of physicochemical properties is critical to developing valid environmental models and risk assessments. Conversely, the predictive/interpretive value of environmental studies is seriously compromised if the physicochemical data upon which they rely are of a questionable or unknown quality [1]. Three of the most important thermophysical properties relating to the environmental behavior of hydrophobic organic compounds are aqueous solubility (Sw), octanol-water partition coef cient (Kow), and Henry’s Law constant (KH). Aqueous solubility is de ned as the maximum amount of solute that can be dissolved in a given amount of solvent. Because Sw is the maximum solute concentration possible at equilibrium, it can also function as a limiting factor in concentration-dependent processes [2]. Inorganic salts, present in large amounts in the environment, greatly inƒuence the partitioning of organic compounds between different phases. The aqueous solubility of organic compounds usually decreases in the presence of inorganic salts, which is known as the salting-out effect. Salting-out offers several practical applications to (1) modify the physical behavior of the solution, (2) separate the components of a system, and (3) improve the sensitivity of analytical techniques.
