Experimental evaluation of plowing and scratch hardness of aqueous two-component polyurethane (2K-PUR) coatings on glass and polycarbonate

Scratch resistance of aqueous two-component (2K-PUR) polyurethane coatings deposited on glass and polycarbonate was investigated by constant mode scratch tests. Penetration and residual depths as well as scratch widths were experimentally evaluated. A first analytical model was applied to estimate plowing and scratch hardness of the polyurethane coatings according to contact pressure and load rate and the corresponding 3D maps were drawn out. The experimental findings allowed mapping the scratch response the polyurethane coatings came through varying the applied load, load rate and substrate compliance, thus establishing the basis for the development of useful tools for failure prediction of the investigated coating systems in a broad range of operational conditions