Evaluation of steel/primer based on chestnut tannin/paint film systems by EIS

S. HORNUS SACK; R. ROMAGNOLI; V.F. VETERE; C.I. ELSNER; O. PARDINI; J.I. AMALVY; A.R. DI SARLI

JOURNAL OF COATINGS TECHNOLOGY

Springer

Año: 2002 vol. 74 p. 63 - 69

0361-8773

The influence of a tannin pretreatment applied to slightly rusted steel panels on the anticorrosive performance of alkyd paint systems has been investigated using electrochemical impedance spectroscopy (EIS) and open circuit potential measurements. From EIS and corrosion potential data analysis it was found that (1) there is not a significant influence of the tannin pretreatment on the anticorrosive protection level, which depends particularly on the barrier effect afforded by the applied paint system (however, as the corrosion process starts, tannins may cause the repassivation of steel); (2) the enhancement of the protection level afforded by the tannin primer was restricted to short immersion periods and corrosive media that were no very aggressive; and (3) water uptake was not significantly affected by the presence of the tannin primer.