Z. Kacarevicpopovic et al., THE SORPTION CHARACTERISTICS AND THERMAL-STABILITY OF EPOXY COATINGS ELECTRODEPOSITED ON STEEL AND STEEL ELECTROCHEMICALLY MODIFIED BY FE-PALLOYS, Progress in organic coatings, 33(1), 1998, pp. 68-75
Citations number
24
Categorie Soggetti
Chemistry Applied","Materials Science, Coatings & Films
The corrosion behaviour and thermal stability of epoxy coatings electr
odeposited on steel and steel electrochemically modified by Fe-P alloy
s of different phase structures have been investigated during exposure
to 3% NaCl. Electrochemical impedance spectroscopy (EIS), gravimetric
liquid sorption experiments and thermogravimetric analysis (TGA) were
used. Epoxy coatings were formed by cathodic electrodeposition of epo
xy resin on steel and steel modified by Fe-P alloys at various current
densities, using a constant voltage method. From the results obtained
from EIS (pore resistance, coating capacitance), gravimetric liquid s
orption experiments (diffusion coefficient) and TGA (water content ins
ide the coating and thermal resistance), it can be concluded that the
electrochemical, transport and thermal properties of epoxy coatings ar
e strongly affected by surface modification of the substrate. The redu
ced electrochemical and transport properties of epoxy coatings on Fe-P
sublayers can be: explained by the catalytic activity of Fe-P alloys
for the Hz evolution reaction, while the improved thermal stability of
these coatings is probably connected with an increasing number of hyd
rogen bonds inside the polymer net. The mechanism of electrolyte penet
ration through an organic coating is also given. (C) 1998 Elsevier Sci
ence S.A.