Fig. 12
Differences between the PHS/PEOX coating on steel seen under the optical microscope. a Scratch of the coating before exposure to humidity in the climatic chamber and b Steel corrosion, after exposing the coating to 90% RH and 35 ℃ for 3 h. c Chemical distribution map of the two polymer components before and after exposure to relative humidity. The same scale in absorbance as in Fig. 10 is followed