Three layer polyolefin coatings: how the FBE primer properties govern the long term adhesion

摘要

Loss of adhesion has been identified on pipelines coated with three layer polyolefin coatings (3LPO) over the past few years. This study was launched by TOTAL to correlate the wet behaviour of commercial fusion bonded epoxy (FBE) primers to the long-term adhesion of related 3LPO systems aged in water. The first part of this paper examines the water uptake behaviour of six FBE grades (free standing films and coatings), and characterises their wet Tg and adhesion. The second part of this paper investigates the long-term adhesion of plant applied 3LPO and related bilayer systems (3LPO without top coat to accelerate the water permeation to sublayers). Adhesion and durability of FBE materials in a wet environment are pointed out as key factors governing the long term adhesion of 3LPO systems.