Taber abrasive wear resistance of organic offshore wind power coatings at varying normal forces

Thirteen organic coatings with three base polymers (epoxy, polysiloxane, polyurethane) were tested in a load-controlled Taber abrasion tester at different normal force levels (2.5 to 25 N). Abrasive wear functions, as well as two partial abrasive wear resistance coefficients, were estimated. Results of scanning electron microscopy (SEM) investigations indicated that both plastic deformation mechanisms and fracture mechanisms caused material removal during the abrasive wear of the materials. The predominant and rate-controlling mechanism depended on normal force and polymer type. Abrasive wear in terms of coating layer thickness loss, as well as the probability of fracture/cracking-based material removal mechanisms, increased with increasing normal force. The ranking of abrasive wear resistance was as follows: epoxy > polysiloxane > polyurethane. The relationship between abrasive wear and normal force followed a power law with power exponents between 0.45 and 1.4. The power exponents were found to depend on the polymer types. The type of polymer was very important for low normal forces, whereas the importance of polymer variation vanished for the higher normal forces.