Durability of fluorinated high density polyethylene geomembrane in the Arctic

A series of fluorinated high density polyethylene (f-HDPE) geomembrane (GM) samples of different thickness (1, 1.5 and 2.5 mm) was exhumed from the backfill immediately upstream of a barrier system constructed to contain a hydrocarbon spill in the Canadian Arctic. The samples were tested for oxidation induction time (OIT), crystallinity, melt index (MI) and tensile properties. The results of these tests are reported and it is shown that the durability of the GM was maintained well beyond the initial 3-year design life of the barrier system. Based on 7 years of field data, the std-OIT depletion time for the 1.5 mm thick GM used in the barrier system was inferred to be over 140 years while the antioxidant depletion time based on the HP-OIT is estimated to be about 200 years. No significant temporal changes in the crystallinity, MI or tensile properties of the exhumed GM samples were detected.