Anti-fouling silicone elastomers for offshore structures

For offshore structures, marine fouling is a major economic and technical problem and the development of the offshore oil and gas industry has led to an increased focus on this topic. Accumulated fouling on the jackets of oil platforms will increase hydrodynamic load on the structure because of increased drag resistance to e.g. tidal current. Fouling also makes inspection and maintenance difficult either because of the need of free-space for non-destructive testing (NDT) or reference markers may be hidden. Hard shell fouling such as barnacles exert pressure on the surface to which they attach themselves and their basal edges can penetrate and undermine the protective coatings, leading to premature corrosion and loss of structural integrity. Controlled release antifouling coatings to combat marine fouling are commonly used. Another approach is to use fouling release (F/R) coating systems which can be silicone materials based on polydimethylsiloxane (PDMS) polymer which is flexible and has a low surface energy. This provides a "self-cleaning" or "easy clean" feature which can be adapted to static structures. This paper will describe experience from the laboratory and the field using silicone based F/R coatings.