On the potential of mitigation of microplastic emission by optimizing anti-erosion coatings

• Novel models to predict erosion fragment size distributions of polymer coatings. • Loading, mechanical properties influence fragment sizes. • The spatial density of internal flaws governs fragment size distributions. • Softer and highly viscoelastic coatings with high fracture toughness led to larger fragments. Surface erosion of polymeric coatings produces microplastic fragments that are released to the environment, acting as a source of microplastics emission. These particles are potentially a danger to human and animal health. In this study, we adopt novel mechanics-based approaches to estimate the size distributions of these fragments and identify key mechanical properties that govern their sizes. We focus mainly on surface erosion of wind turbine blades, but our models have broad applicability. In our approaches we consider that fragments are formed due to the growth and coalescence of microcracks due to repetitive rain droplet impacts. Our findings suggest that viscoelastic and tough coatings which can tolerate larger flaws without fatigue microcrack initiation, softer coatings which decrease the peak impact stresses, and a smaller density of inherent material flaws will all lead to larger fragments.