The impact of hardener concentration, curing temperature, thickness and Alumina Trihydrate (ATH) on superhydrophobic modified-polyurethane coatings for insulators

In this study, the influence of curing temperature, hardener concentration, thickness and ATH on the performance of superhydrophobic polyurethane insulator coating is evaluated. Nanosilica particles with a concentration of 8wt% and an organosilane as hydrophobic agent were mixed with a polyurethane (PU) coating. It was found that coatings with advancing contact angle of 157° and CAH of 6° could be prepared by adjusting the formulation. The results indicated that the increase of hardener concentration could improve the hydrophobicity and rubbing durability of coatings. Also, it was observed that an increase in curing temperature up to 120 °C could improve the superhydrophobic property of coatings. The increase of coating thickness could reduce the contact angle and the surface roughness of the prepared coatings. The ATH was found to be compatible with superhydrophobic modified-PU coatings and did not reduce the hydrophobic and mechanical property of coatings.