Susceptibility of ABS, FEP, FRE, FRP, PTFE, and PVC Well Casings to Degradation by Chemicals.

This study compares the chemical resistance of four less commonly used materials for casing groundwater monitoring wells acrylonitrile butadiene styrene ABS, fluorinated ethylene propylene FEP, fiberglass-reinforced epoxy FRE, and fiberglass-reinforced plastic FRP, with two more commonly used casing materials polyvinyl chloride PVC and polytetrafluoroethylene PTFE. The six materials were exposed to 28 neat organic compounds including one acid and to extremely acidic and alkaline conditions for up to 112 days. This was done to simulate some of the most aggressive environments that monitoring well casings may be exposed to. The casings were observed for changes in weight and signs of physical degradation swelling, softening, decrease in strength, deterioration, or dissolution. As expected, the two fluorinated polymers FEP and PTFE were the most inert materials tested. They were not degraded by any of the test chemicals, although samples exposed to a few organic chemicals did show a slight weight gain approx. 1. Among the nonfluorinated products tested, FRE was the most inert. Three organic chemicals caused particles to flake from the FRE surface, followed by separation of the glass fibers, and two organic chemicals caused weight gains exceeding 10. Also, highly acidic conditions pH1 degraded this material, and this may limit the use of this material in acidic environments. jg