Network structure in marine protective coatings: Correlating PALS, Neutron Scattering and Diffusion to improve Wind Turbine lifetimes

Wind turbines and in particular off-shore wind turbines have been the mainstay of zero carbon energy production in the UK. They are protected by epoxy resins that are required to resist the harsh climate out at sea. Whilst the blades are made mainly from glass fibre, the masts are steel. These masts are liable to corrode and thus the protective coating is a critical component in this assembly. Currently these masts are regularly inspected, initially manually, more recently drones are being used. Prolonging the life expectancy of the coating in any way would reduce the need for inspection. Understanding how water permeates the structure of epoxy resins in both filled (with corrosion inhibitors) and unfilled epoxy systems is key. Additionally, bulk tankers carry chemicals (e.g. methanol) around the world, epoxy resin is also used here as a protective coating. We have collected both water diffusion, SANS and PALS (positron annihilation lifetime spectroscopy) data to understand the structure of the epoxy systems and by using deuterated water or methanol, how these locate in the epoxy. PALS indicates structures on the order of 0.2 nm. While SANS indicates much larger structures, however the SANS does not deliver the higher Q data to corroborate the PALS data. We wish to undertake a series of NIMROD measurements to determine the structure of dry, partially and fully humidified (D2O) epoxy resin films.