The effect of SO2 and NaCl in the degradation of organic coatings

IODOMETRIC TITRATION and ion-selective electrode techniques were used to determine the transmission rates of sulphur dioxide and chloride ions through five commercial priming paints. Results showed an approximately three to four orders of magnitude higher SO2 permeation than that of the chloride ions. Nevertheless, it is necessary to use other experimental techniques to select the paint with the best performance for a given environment. Adhesion measurements in dry state were useful for the above selection, which was verified by electrochemical polarization resistance.

Adhesion; Degradation; Electrochemistry; Ion selective electrodes; Mechanical permeability; Polarization; Protective coatings; Sodium chloride; Sulfur dioxide; Titration; Electrochemical polarization resistance; Iodometric titration; Organic coatings; coating; corrosion; steel; sulfur dioxide

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