Settling data of offshore corrosion protection coating particles under varying environmental conditions

Artificial marine structures are commonly built from steel and need protection against corrosion in the marine environment to maintain the structure's longevity. The most common corrosion protection method is the application of corrosion protection coatings made from epoxy resin and polyurethane on the steel surface. These corrosion protection coatings deteriorate, detach with time, and enter the marine environment as particle emissions, where they sink towards the seabed due to the negatively-buoyant characteristics of the used materials. In this study, the settling process is investigated in laboratory conditions for controlled samples of coating particles made from single-layer epoxy resin, single-layer polyurethane, and double-layer epoxy/polyurethane particles. The particles sank in still water, employing three different ambient salinities in an acrylic column. The effects of UV-weathering and biofilm on the particle's surface were additionally investigated, to better understand how exposure duration of the coatings to the marine environment might alter the settling dynamics. Separated by particle size and shape, terminal settling velocities and drag coefficients were determined for all particles used in the experiments.