Erosion of the leading edge is one of the most severe forms of damage in wind turbine blades, particularly in offshore wind farms. This degradation, mainly caused by rain, sand, and airborne particles through droplet impingement wear, significantly decreases blade aerodynamic efficiency and power output. Since blades, typically made of fiber-reinforced polymer composites, are the most expensive components of a turbine, developing protective coatings is essential. In this study, polyurethane (PU) composite coatings reinforced with titanium dioxide (TiO₂) particles were added on glass fiber substrates by spray coating. The incorporation of TiO₂ improved the mechanical and electrochemical performance of the PU coatings. FTIR and XRD confirmed that low TiO₂ loadings (1 and 3 wt%) were well dispersed within the PU matrix due to hydrogen bonding between TiO₂ –OH groups and PU –NH groups. The PU/TiO₂ 3% coating exhibited ~61% lower corrosion current density (I_corr) compared to neat PU, indicating superior corrosion resistance. Furthermore, uniform TiO₂ dispersion resulted in statistically significant improvements (p < 0.05) in hardness, yield strength, elastic modulus, and adhesion strength. Overall, the PU/TiO₂ coatings, particularly at 3 wt% loading, show strong potential as protective materials for wind turbine blades, given their enhanced mechanical integrity and corrosion resistance.

Wind turbine blades are made from fiberglass, whose faces are eroded due to environmental conditions. Polyurethane (PU) coatings are broadly used in several types of coatings due to their strong adhesion. However, their inferior mechanical properties limit their application on fiberglass. In this study, graphene oxide (GO) was modified through a dielectric barrier plasma (DBP) treatment at atmospheric pressure to improve the dispersion of GO in PU and increase its adhesion to fiberglass (GF) substrates, resulting in excellent adhesion properties of the PU/GO coating on fiberglass. Additionally, PU/GO coatings are crucial for preventing and protecting against erosion. The results obtained for the intensity ratio of the $I_D/I_G$ peaks observed through Raman spectroscopy exhibited that the plasma treatment increased the defects in the GO structure through covalent and non-covalent interactions with the PU. Contact angle tests and surface free energy measurements indicated the deoxygenation of the GO structure, enhancing its dispersion in the PU matrix, as observed through XRD. The plasma treatment increased the PU/GO adhesion by 27.6% after 10 min of treatment, suggesting that more defects in the GO structure were correlated with greater adhesion strength.

In this investigation, we studied the influence of atmospheric pressure plasma treatment on the surface properties of polypropylene (PP). The PP samples were treated for various durations using a gliding arc plasma source with air as a working gas. The formation of polar groups (–OH and C = O) on the PP surface after plasma treatment was evaluated and analyzed using Raman spectroscopy and attenuated total reflection–Fourier transform infrared spectroscopy. The contact angle was measured using polar and non-polar liquids to obtain the polar and dispersive components as well as the surface free energy of the PP before and after treatment. A sevenfold increase after treatment was observed for the polar component, while hydrophobicity decreased 73% after treatment. Finally, changes in topography were observed using atomic force microscopy (AFM) analysis before and after plasma treatment. AFM images showed that under atmospheric treatment, the PP surface underwent etching, reducing the surface roughness. Microhardness measurements of the films also revealed significant changes in mechanical properties after plasma treatment.