Geomembranes in use as liners of landfills and other waste containment structures are subject to both chemical and mechanical attacks. The ability of the geomembrane to maintain its integrity in the face of these attacks is of major concern in the prevention of discharges from the waste disposal facility. In this work, geomembranes were subjected to simultaneous chemical exposure and mechanical loads using the comprehensive testing system (CTS). The chemicals selected were gasoline and surrogatesselected on the basis of either health-based environmental concern related to the chemical's release, or their use in ASTM (American Society of Testing and Materials) testing of rubbers exposed to gasoline. The thermodynamics of polymer-solventinteraction, expressed as cohesive energy density, was extended to binary-component mixtures and used to model the change in the mechanical performance of the geomembrane as measured by the CTS test parameter, ΔE, ΔE It was found that a volume-fractionbased thermodynamic mixing rule for the binary mixtures, consistent with regular solution theory, explained changes in theΔE of the geomembrane. A nonlinear model provided the ability to predictΔE as a function of the difference between the cohesiveenergy density of the solvent and the polymer.
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