THE DURABILITY OF HDPE GEOMEMBRANES

Abstract

This paper considers the durability of high density polyethylene (HDPE) geomembranes, in particular aspects that relate to the composition and structure of the material. The difference between high and low density polyethylene is explained. The effect of crystalline structure and the addition of comonomers on properties is outlined. HDPE is generally inert but under conditions of high concentrations of oxidising agent and a sufficient supply of energy, oxidation may occur. The process is described. Physical interaction with organic chemicals, in particular solvation with aromatic or halogenated solvents is described. The process of extraction of additives is outlined. It is suggested that once installed, geomembranes are not generally exposed to sufficient oxygen or energy sources to be degraded. The effects of ageing are considered to be insignificant. Valuations made of durability in the United States suggest a life of 'hundreds of years'.