Chemical Effects on Flexible‐Membrane Liner Seams

Abstract

Twelve‐month exposure data were completed on 37 different seamed‐membrane materials. Seaming methods described and evaluated include adhesive bonding, bodied‐solvent bonding, solvent adhesive, and thermal methods resulting in polymer melting. The seamed materials were exposed in 10% phenol (organic acid), 10% HC1 (inorganic acid), 10% NaOH (inorganic base), 10% MEK (ketone), 5% furfural (aldehyde), and 100% methylene chloride (halogenated hydrocarbon). Assessment by shear and peel testing showed that materials not having chemical resistance had significant property reduction after only three months of exposure. Thermally produced seams had better resistance than did those based on solvent or adhesive bonding. For reinforced materials, the predominant failures in shear were associated with scrim failure and pull‐out, and failures in peel were evenly distributed between ply separation scrim breakage or adhesive‐bond‐system failure‐scrim delamination and pull‐out. For nonreinforced materials, failures in shear were mostly in parent material, and failures in peel occurred either in parent material or between the adhesive and the liner surface.