The effect of thickness on the depletion of antioxidants (AO) from high density polyethylene (HDPE) geomembranes (GMBs) in accelerated aging tests is investigated. Testing was conducted on three different GMBs manufactured from the same resin and production lot. The GMBs were aged in synthetic leachate at five different temperatures and the depletion of AO was monitored. The results show that the AO depletion rates varied inversely with GMB thickness, with thicker GMBs likely having a longer service life than thinner GMBs (other things being equal). However, the rate of depletion is not only governed by the GMB thickness but also by the morphological structure of the GMB which results from the manufacturing process.
First presented at GeoAmericas 2012.